BIOLOGICAL AND PHYSICAL FACTORS AFFECTING CATCH OF HOUSE FLIES

IN ULTRAVIOLET LIGHT TRAPS

By

MATTHEW D. AUBUCHON

A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT

OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2006

Copyright 2006

by

Matthew D. Aubuchon

iii

ACKNOWLEDGMENTS

I would like to sincerely thank Dr. Phil G. Koehler for directing the course of this

dissertation and my graduate program. I would also like to acknowledge and thank Dr.

Faith Oi, Dr. Norm Leppla, Dr. Nancy Hinkle, Dr. Jerry Hogsette, and Dr. Ron Randles

for their service on my supervisory committee. Ricky Vasquez, Ryan Welch, and Jeff

Hertz provided valuable assistance with house-fly rearing. Dr. Phil Kaufman graciously

made space in his laboratory for us to rear our house flies and provided valuable rearing

advice. Debbie Hall was extraordinarily helpful to me with registration, research credits,

graduate-school deadlines, and all other associated paperwork. I would like to thank my

family for their support through this process. Finally, I would like to thank my beautiful

wife Amanda for her love, support, encouragement, and patience throughout my graduate

school experience.

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TABLE OF CONTENTS page

ACKNOWLEDGMENTS ................................................................................................. iii

LIST OF TABLES............................................................................................................. vi

LIST OF FIGURES .......................................................................................................... vii

ABSTRACT.........................................................................................................................x

CHAPTER

1 INTRODUCTION AND LITERATURE REVIEW ....................................................1

The House Fly Musca domestica..................................................................................1 Importance of Musca domestica ...................................................................................1

Nuisance ................................................................................................................1 Disease Transmission ............................................................................................2

Biology of Musca domestica ........................................................................................4 Oviposition ............................................................................................................4 Larval Development and Survival.........................................................................4 Adult Behavior ......................................................................................................6

Activity and longevity ....................................................................................6 Photoperiod ....................................................................................................7 Dispersal.........................................................................................................8

Attractants for Musca domestica ..................................................................................9 Chemical Attractants .............................................................................................9 Physical Attractants ...............................................................................................9

Color...............................................................................................................9 Surfaces ........................................................................................................10 Light .............................................................................................................11

Control Using Attractants ...........................................................................................13 Chemical Baits.....................................................................................................13 Physical Traps .....................................................................................................13 Insect Light Traps (ILT)......................................................................................14

House Fly Response to ILTs ........................................................................14 Design and Location of ILTs .......................................................................15 Competing Light Sources.............................................................................16

Statement of Purpose ..................................................................................................18

v

2 ESTIMATES OF RESPONSE TIME BY HOUSE FLIES TOWARD UV LIGHT TRAPS USING LIGHT-TUNNEL BIOASSAY .......................................................20

Introduction.................................................................................................................20 Materials and Methods ...............................................................................................21 Results and Discussion ...............................................................................................25

3 INFLUENCES OF QUALITY AND INTENSITY OF BACKGROUND LIGHT ON HOUSE FLY RESPONSE TO LIGHT TRAPS..................................................37

Introduction.................................................................................................................37 Materials and Methods ...............................................................................................38 Results and Discussion ...............................................................................................43

4 LIGHT TRAP HABITUATION STUDY ..................................................................63

Introduction.................................................................................................................63 Materials and Methods ...............................................................................................63 Results and Discussion ...............................................................................................67

5 SUMMARY AND CONCLUSIONS.........................................................................73

APPENDIX

A DIAGRAM OF BUILDING LAYOUT .....................................................................76

B SAS PROGRAMS USED FOR DATA ANALYSIS.................................................77

SAS programs for Chapter 2.......................................................................................77 SAS programs for Chapter 3.......................................................................................79 SAS Programs for Chapter 4 ......................................................................................81

C SPECTROMETRY MEASUREMENTS FOR LIGHT TRAPS AND BACKGROUND LIGHT ...........................................................................................82

D REARING CONDITIONS FOR CONLONIES OF MUSCA DOMESTICA .............90

LIST OF REFERENCES...................................................................................................96

BIOGRAPHICAL SKETCH ...........................................................................................105

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LIST OF TABLES

Table page 2-1 Effect of building, position within building, and box enclosure on the number of

house flies caught in UV light traps (50 M: 50 F per repetition). ............................30

2-2 Influence of age and sex on number of house flies caught in UV light traps (50 M: 50 F per repetition) ...................................................................................................31

2-3 Cumulative house-fly catch in UV light traps over time (50 M: 50 F per repetition)32

2-4 Estimated time (h) to catch of adult house flies by UV light traps using Probit analysis .....................................................................................................................33

3-1 Light intensity (lumens/m2) measured within five local restaurants (R) and grocery stores (G) ..................................................................................................................48

3-2 Light intensity (lumens/m2) of four intensity treatments of cool-white fluorescent light measured 45 cm from light source...................................................................48

3-3 Effect of intensity of cool-white fluorescent light as a competing light source on number of adult house flies (mean ± SE) caught in UV light traps (50 M: 50 F per repetition) .................................................................................................................49

3-4 Estimated intensity (lumens/m2) of total spectral output, blue-green output, and ultraviolet output emitted from competing light sources and light traps used in light quantity experiments ................................................................................................50

3-5 Effect of competing light quality on mean number (± SE) of adult house flies caught in UV light traps (50 M: 50 F per repetition) ...............................................51

3-6 Estimated intensity (lumens/m2) of total spectral output, blue-green output, and ultraviolet output emitted from competing light sources and light traps used in light quality experiments ..................................................................................................52

4-1 Mean number of adult house flies caught in UV light traps after being pre-conditioned under different light conditions. ...........................................................69

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LIST OF FIGURES

Figure page 2-1 Light tunnel design illustrating release cage (30 by 30 by 45 cm) (foreground),

overhead light source (101.6 cm), light tunnel (152 by 20 cm), and box enclosure (66 by 91 by 60 cm) containing light trap................................................................34

2-2 Intensity (lumens / m2) of UV-light trap with relative intensity of light by wavelength ...............................................................................................................35

2-3 Intensity (lumens/m2) of cool-white fluorescent light with relative intensity of light by wavelength ..........................................................................................................36

3-1 Spectral analysis and mean intensity (lumens/m2) of 1 Sylvania® Cool White fluorescent bulb measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm..........................................................................................53

3-2 Spectral analysis and mean intensity (lumens/m2) of 2 Sylvania® Cool White fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. ................................................................................54

3-3 Spectral analysis and mean intensity (lumens/m2) of 3 Sylvania® Cool White fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. ................................................................................55

3-4 Spectral analysis and mean intensity (lumens/m2) of 4 Sylvania® Cool White fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. ................................................................................56

3-5 Regression analysis showing relationship between trap catch and intensity (lumens/m2) of blue-green light...............................................................................57

3-6 Spectral analysis and mean intensity (lumens/m2) of Sylvania® Blacklight bulbs measured at 61 cm from source. Arrow highlights UV peak between 340 and 370 nm.............................................................................................................................58

3-7 Spectral analysis and mean intensity (lumens/m2) of Sylvania® Daylight fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. .......................................................................................................59

viii

3-8 Spectral analysis and mean intensity (lumens/m2) of Sylvania® Cool White fluorescent light measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. ................................................................................60

3-9 Spectral analysis and mean intensity (lumens/m2) of Sylvania® Warm White fluorescent light measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm. ................................................................................61

3-10 Regression analysis showing relationship between trap catch and intensity (lumens/m2) of blue-green light...............................................................................62

4-1 Spectral analysis and mean intensity of GE® Plant & Aquarium fluorescent light used in house fly rearing room. Mean light intensity presented in lumens/m2. ......70

4-2 Spectral analysis and mean intensity of Sylvania® Blacklight used to rear treatment house flies. Mean light intensity presented in lumens/m2. ......................................71

4-3 Spectral analysis and mean intensity of Sylvania® Cool White fluorescent light used to rear treatment house flies. Mean light intensity presented in lumens/m2. ..72

A-1 Diagram of buildings, positions, and bioassay layout at USDA..............................76

C-1 Spectral analysis and mean light intensity of Whitmire Nova trap 1 at Position a1.82

C-2 Spectral analysis and mean light intensity of Whitmire Nova trap 2 at Position a2.83

C-3 Spectral analysis and mean light intensity of Whitmire Nova trap 3 at Position b1 84

C-4 Spectral analysis and mean light intensity of Whitmire Nova trap 4 at Position b2 85

C-5 Spectral analysis and mean intensity of overhead cool-white fluorescent light at Position a1.................................................................................................................86

C-6 Spectral analysis and mean intensity overhead cool-white fluorescent light at Position a2.................................................................................................................87

C-7 Spectral analysis and mean intensity overhead cool-white fluorescent light at Position b1 ................................................................................................................88

C-8 Spectral analysis and mean intensity overhead cool-white fluorescent light at Position b2 ................................................................................................................89

D-1 Temperature (C°) of rearing room for adult Musca domestica recorded by HOBO Temp & RH data logger ...........................................................................................90

D-2 Relative Humidity (%) of rearing room for adult Musca domestica recorded by HOBO Temp & RH data logger...............................................................................91

ix

D-3 Light intensity (lumens/m2) of rearing room for adult Musca domestica recorded by HOBO Light Intensity data logger. Graph illustrates 12:12 (L:D) photoperiod .....92

D-4 Temperature (C°) of rearing room for Musca domestica larvae recorded by HOBO Temp & RH data logger ...........................................................................................93

D-5 Relative Humidity (%) of rearing room for Musca domestica larvae recorded by HOBO Temp & RH data logger...............................................................................94

D-6 Light intensity (lumens/m2) of rearing room for Musca domestica larvae recorded by HOBO Light Intensity data logger. Graph illustrates 12:12 (L:D) photoperiod95

x

Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

BIOLOGICAL AND PHYSICAL FACTORS AFFECTING CATCH OF HOUSE FLIES IN ULTRAVIOLET LIGHT TRAPS

By

Matthew D. Aubuchon

May 2006

Chair: Phil Koehler Major Department: Entomology and Nematology

A bioassay for studying light trap efficacy for the house fly Musca domestica L.

(Diptera: Muscidae) was developed to overcome position effects associated with light-

trap placement. After initial studies, no significant effects of position were detected

among two research buildings, four positions, or box enclosures used. The light-tunnel

bioassay provided standardized air movement, trap location, trap distance, and

background light for future experiments investigating house fly age and response time.

House flies that were 5 d and younger showed significantly greater attraction toward UV

light traps than older flies. A probit analysis estimated that catch time for 50% of house

flies (CT50) toward UV traps ranged from 99 to 114 min for males and females

respectively. Estimated CT50 for total house fly response toward UV light trap was

approximately 1.72 h (103.2 min). The CT90 and CT95 estimates for total house fly catch

were 6.01 h (360.6 min) and 8.57 h (514.2 min) for males and females respectively. No

xi

significant difference between male and female response time was seen by overlapping

95% confidence intervals for CT50, CT90, and CT95.

When flies were presented greater intensity levels of cool-white fluorescent light,

the number of males caught in UV traps significantly decreased when intensity of the

competing light exceeded 51.43 lumens/m2. Significant declines in catch of females

occurred at a lower intensity when the competing light exceeded 27.43 lumens/m2. When

the data were combined, overall results showed that the total catch in UV light traps

decreased significantly as the intensity of competing light source increased. Results of

our lab study showed a significant decrease in response of male and female house flies

toward UV light traps as the intensity of competing fluorescent light was increased.

When house flies were presented four different types of competing light, all

responses were significantly different when compared with the dark control. However,

house fly response toward UV light traps was significantly lower when background light

contained broad-based UV versus background light containing blue-green light.

For habituation experiments, all treatments caught significantly fewer house flies

than the dark control. However, there was no significant difference in the response to

UV light traps among house flies reared on UV light, cool-white fluorescent light, and the

grow-lights used in the rearing rooms. The quality of light used in rearing did not

significantly influence house fly response to UV light traps.

1

CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW

The House Fly Musca domestica

The house fly Musca domestica L. (Diptera: Muscidae) is a synanthropic filth fly

that breeds in garbage, and animal and human feces (Schoof and Silverly 1954a,

Greenberg 1973, Imai 1984, Graczyk et al. 2001). It is a dull gray insect and may be

identified by four longitudinal stripes on the dorsum of the thorax and a sharp angle on

the fourth longitudinal wing vein (West 1951). The house fly does not bite as it is

equipped with sponging-rasping mouthparts (West 1951, McAlpine 1987).

Musca domestica L. is classified in the order Diptera and family Muscidae

(McAlpine 1987, Borror et al. 1989). Flies in the family Muscidae generally have strong

setae dispersed over the entire body, dull color, and reduced wing veination (West 1951,

McAlpine 1987). The Genus Musca encompasses approximately 24 species with 2

subspecies of M. domestica (West 1951). Because house flies adapt to human

environments, they are found on all continents except Antarctica (West 1951, McAlpine

1987).

Importance of Musca domestica

Nuisance

House flies are a nuisance in agricultural and urban environments (Cosse and Baker

1996, Moon 2002, Hogsette 2003). Large populations populations originating from

animal manure can cause economic losses in livestock (Axtell 1970, Hogsette and Farkas

2000). Dispersing house flies are pestiferous in residential and commercial areas and

2

present a public health problem to home and business owners near agricultural areas

(Axtell 1970, Hogsette 2003). Breeding sites such as animal waste and garbage

dumpsters contribute to problems associated with house flies in urban environments

(Schoof and Silverly 1954b, Morris and Hansen 1966).

Disease Transmission

House flies have been implicated as mechanical vectors of a range of enteric

pathogens among animals and humans (Schoof and Silverly 1954a, Greenberg 1973, Imai

1984, Graczyk et al. 2001). Viruses, bacteria, and protozoans cling to house fly wings,

setae, tarsi, and mouthparts and are dislodged onto a variety of surfaces (Graczyk et al.

2001). In poultry houses and dairy units, house flies were a primary vector of Salmonella

spp. (Mian et al. 2002). Salmonella spp. and Shigella spp. (which causes morbidity and

mortality associated with infantile gastroenteritis), are also transmitted by house flies to

humans (Bidawid et al. 1978). Levine and Levine (1991) reported that the incidence of

dysentery coincided with the seasonal prevalence of house flies. As house flies acquired

Shigella spp. from human feces in open latrines, they contaminated open food markets,

hospitals, slaughter houses, and animal farms (Levine and Levine 1991, Graczyk et al.

2001). A high density of open markets with rotting fish, meats, and vegetable matter

combined with close proximity of food markets to slaughter houses encouraged outbreaks

of house flies (Bidawid et al. 1978). Incidentally, a high density of humans lacking

infrastructure and garbage pick-up compounded the health risks associated with house fly

outbreaks (Bidawid et al. 1978). In addition to Salmonella spp. and Shigella spp., house

flies transmit other enteric disease organisms such as Campylobacter spp. or

enterohemorrhagic E. coli, which cause morbidity and mortality in humans resulting from

diarrheal illnesses (Graczyk et al. 2001). Helminthic parasites have also been transported

3

on house fly exoskeletons and rotavirus may be transported on legs and wings, then

dislodged by flight motion (Monzon et al. 1991, Tan et al. 1997).

In hospitals, house flies can play a vital role as vectors of resistant strains of enteric

pathogens among patients (Rady et al. 1992). Pathogens such as Klebsiella spp.,

Enterococcus faecalis, and others have been distributed by house flies within patient

wards (Graczyk et al. 2001). Many strains are acquired by house flies from patients and

some strains are resistant to antibiotics (Graczyk et al. 2001). Rady (1992) isolated

Enterobacteriaceae, Micrococcaceae, Corynebacteriaceae, Brucellaceae, and

Pseudomonodaceae from house flies trapped in hospitals. Among the aforementioned

families of bacteria, some may cause septicemia in humans (Rady et al. 1992).

Although house flies primarily transport disease agents on their wings, tarsi, and

setae, they may also spread pathogens by regurgitation and fecal deposition (Graczyk et

al. 2001). In developing countries, house flies are important vectors of Chlamydia

trachomatis, which causes blindness in humans (Graczyk et al. 2001). Flies carry C.

trachomatis on their legs and probosces, and the agent survives in the gut for 6 hours

(Graczyk et al. 2001). In laboratory studies, Helicobacter pylori was isolated from

external surfaces of house flies up to 12 hours after exposure (Gruebel et al. 1997).

However, H. pylori (responsible for gastroduodenal disease), was also isolated from gut

and excreta of house flies up to 30 hours after initial feeding by house flies (Gruebel et al.

1997). Helicobacter organisms attached to intestinal epithelial walls of house fly guts

suggested that house flies were a reservoir as well as a vector (Gruebel et al. 1997).

Other bacteria isolated from the digestive tract of house flies included Klebsiella oxytoca,

Enterobacter agglomerans, Burkholderia pseudomallei, Citrobacter freundii, and

4

Aeromonos hydrophila (Sulaiman et al. 2000). Yersinia pseudotuberculosis survived in

the house fly digestive tract up to 36 hours after exposure (Zurek et al. 2001). House

flies may contaminate a surface with Y. pseudotuberculosis by regurgitating their crop

content (Zurek et al. 2001).

Recent studies implicate house flies as vectors of Enterohemorrhagic Escherichia

coli (EHEC) 0157:H7) which causes enteric hemorrhagic disease in humans. House flies

acquired EHEC 0157:H7 from cow dung and were capable of transmitting EHEC

0157:H7 (Iwasa et al. 1999). The EHEC 0157:H7 proliferated in mouthparts of house fly

where it may be ingested and disseminated by fecal deposition (Sasaki et al. 2000).

Ingested EHEC 0157:H7 remained inside the crop for 4 days and was detected in fecal

drops (Sasaki et al. 2000).

Biology of Musca domestica

Oviposition

House flies are holometabolous insects with distinct egg, larval, pupal, and adult

stages (West 1951, Sacca 1964). Within 1 day of becoming gravid, adult females seek

decaying organic material and animal feces for their eggs (Krafsur 1985, Hogsette 1996,

Graczyk et al. 2001). Female house flies may lay 5 to 6 batches of eggs, with each batch

containing 75 to 150 eggs (Hogsette 1996, Graczyk et al. 2001).

Larval Development and Survival

House fly larvae develop in decaying organic material, including manure, and have

three distinct larval stages (West 1951, McAlpine 1987). Larvae are milky white with a

cylindrical shape that tapers anteriorly (McAlpine 1987). The posterior of M. domestica

larvae is blunt and exhibits heavily scleritized posterior spiracles (McAlpine 1987).

5

Temperature of breeding sites directly affects the rate of larval development (Sacca

1964, Elvin and Krafsur 1984, Lysyk 1991b, Barnard and Geden 1993, Hogsette 1996).

Developmental time from egg to adult may range from 6 days under optimal temperature

conditions to 50 days (Barnard and Geden 1993). Haupt and Busvine (1968) reported

that lower temperatures prolonged house-fly development and enhanced larval size.

Sacca (1964) documented that 35 to 38°C was an optimal temperature range for larval

development. Although higher temperature enhanced the rate of development, Barnard

and Geden (1993) found that larval survival was highest between 17°C and 32°C.

Moisture levels within house fly breeding sites affect their survival. Animal

manure moisture content ranging from 50 to 70% yielded significantly more flies than

drier manure (Hulley 1986, Fatchurochim et al. 1989). Fatchurochim et al. (1989)

reported a significant decline in house fly survival in manure containing less than 40% or

more than 80% moisture. In addition, Hulley (1986) observed that manure with low

moisture levels encouraged parasitism by pteromalid wasps. However, Hogsette (1996)

found that some house flies could survive in manure containing less than 5% moisture,

suggesting that house flies may survive under extreme conditions.

Survival of house fly larvae is also influenced by larval density within breeding

sites. Haupt and Busvine (1968) and Barnard et al. (1998) observed inverse relationships

between density and larval size and larval weight. Smaller larvae ultimately developed

into smaller pupae and adults (Barnard et al. 1998). Larval mortality was significantly

greater at high densities versus lower densities, while intermediate larval densities

produce more viable progeny (Haupt and Busvine 1968, Bryant 1970). Bryant (1970)

hypothesized that breeding sites conditioned by presence of larval densities regulated

6

oviposition rates, and thus egg densities in natural populations maintained an optimal

density.

Adult Behavior

Activity and longevity

Behavior and activity of adult house flies changes with age. As male house flies

age, wing function declined due to age and damage caused by mating attempts rendering

them flightless within 12 days (Ragland and Sohal 1973). Mating activity, like flight

activity, also declined with age.

Flight activity of M. domestica may be influenced by temperature and age. House

flies are mobile between 14 and 40°C but peak flight activity occurs between 20 and

30°C (Tsutsumi 1968, Luvchiev et al. 1985). Flight activity significantly decreased

above 35°C and activity ceased above and below 20°C, but high relative humidity

contributed to a 2- to 3-fold increase in flight activity (Tsutsumi 1968, Buchan and Sohal

1981, Luvchiev et al. 1985). Since higher temperatures induced greater house fly

activity, Buchan and Moreton (1981) observed that house fly lifespan significantly

decreased at higher temperatures. They hypothesized that higher temperatures induced a

higher metabolism, suggesting that the house fly rate of living also increased (Buchan

and Moreton 1981, Buchan and Sohal 1981). Later experiments confirmed that life

expectancy of both sexes significantly declined as temperature increased from 20 to 35°C

(Fletcher et al. 1990, Lysyk 1991a).

Population density may also influence longevity of adult house flies. The life

expectancy in the lab may range between 12 and 30 days for adult male house flies and

between 11 and 44 days for adult females (Ragland and Sohal 1973, Fletcher et al. 1990).

7

Caged experiments using adult house flies showed an inverse relationship between adult

life expectancy and population density (Rockstein et al. 1981). Susceptibility to high

mortality associated with high density was greater for males than females (Haupt and

Busvine 1968). Field experiments using artificial garbage dumps showed exponential

growth of fly populations within 1 month of dumping the garbage and confirmed that as

density increases, survivability decreases (Imai 1984, Krafsur 1985). Both adult males

and females also showed an inverse relationship between life expectancy and mate access

(Ragland and Sohal 1973).

Dietary restrictions may also influence life expectancy and activity of adult house

flies. Rockstein et al. (1981) reported that protein-starved house flies of both sexes had a

significantly lower life expectancy than protein-satiated flies. Adding sucrose for house

flies reared on manure or powdered milk significantly increased the longevity of both

sexes (Lysyk 1991a). Starved flies and flies fed on sugar-only diets were significantly

more active than protein-satiated house flies (Tsutsumi 1968, Skovmand and Mourier

1986). Conversely, replete flies rested and showed a significantly higher frequency of

regurgitation and resting behaviors (Tsutsumi 1968).

Photoperiod

House flies are diurnal insects whose activity is directly related to light intensity

(Tsutsumi 1968, Sucharit and Tumrasvin 1981). Adult house flies entrained on a 12:12

(L:D) photoperiod showed resting behavior induced by lower light levels, and ceased

flight activity at the onset of night even when the photoperiod was removed (Tsutsumi

1968). Although peak activity times ranged from 9AM to 4PM, continuous brightness

ultimately suppressed the circadian rhythm of the house fly and complete darkness

inhibited house fly activity (Tsutsumi 1968, Meyer et al. 1978, Semakula et al. 1989).

8

Dispersal

House flies are disease vectors capable of dispersing between 5 and 20 miles from

their point of origin (Schoof and Silverly 1954b, Morris and Hansen 1966). Initial mark-

recapture studies showed that flies dispersed randomly and approximately 50% of

150,000 released flies were captured within ½ mile from their initial release point

(Schoof and Silverly 1954b). It was estimated that flies migrate 0.5 miles to 2.5 miles

over a period of 1-5 days (Morris and Hansen 1966). However, a lack of available

breeding sites encouraged flies to disperse up to ½ mile within 3 to 8 hours (Pickens et al.

1967). Although dispersal was random, Pickens et al. (1967) observed house flies were 2

to 3 times more likely to disperse from clean dairy farms versus unsanitary farms with

multiple breeding sites.

Environmental factors such as wind may also affect dispersal (Morris and Hansen

1966). Strong down winds may aid in dispersal, but house flies have been observed

flying upwind of breezes between 2 and 7 mph (Morris and Hansen 1966, Pickens et al.

1967).

In poultry and dairy units containing great abundance of animal manure, house flies

dispersed approximately 50 meters (Lysyk and Axtell 1986, Hogsette et al. 1993) .

Rather than density-dependent mortality in field studies, evidence shows density-

dependent dispersal toward better habitat (Imai 1984, Krafsur 1985). However, studies in

poultry houses showed house fly distribution downwind was twice as great as upwind

with dead-air zones containing the greatest abundance of adults (Geden et al. 1999).

9

Attractants for Musca domestica

Chemical Attractants

House flies respond to a wide variety of chemical or odorous attractants. In initial

studies, excrement and decomposing organic material attracted significant numbers of

house flies into containment traps (West 1951, Mulla et al. 1977). Food baits composed

of sugar, molasses, putrified egg extracts, or chicken and rice were also successful

attractants or served as a medium for insecticides (Pickens et al. 1973, Mulla et al. 1977,

Pickens et al. 1994, Pickens 1995). Other studies using an odorous “dumpster recipe”

caught significant numbers of house and stable flies, but such attractants may be limited

to the outdoors (Pickens et al. 1975, Rutz et al. 1988).

The discovery and synthesis of the female sex pheromone (Z)-9-tricosene led to the

development of muscalure and enhanced the efficacy of synthetic fly baits (Carlson and

Beroza 1973, Carlson et al. 1974). Although (Z)-9-tricosene is produced by females,

field trials showed significant attraction of both male and female house flies (Pickens et

al. 1975, Rutz et al. 1988, Chapman et al. 1999). High concentration of (Z)-9-tricosene

many act as an aggregation pheromone for both sexes of M. domestica (Chapman et al.

1998).

Physical Attractants

Color

House flies respond to a variety of environmental factors such as color, light

quality, light reflectance, and color contrast (Hecht 1970). High color saturation of a

surface combined with a strong contrast between that surface and its surrounding

environment was thought to be more attractive to M. domestica than individual colors,

however their response to individual colors seemed to change with temperature (Pickens

10

et al. 1969, Hecht 1970, Green 1984, Bellingham 1995, Snell 1998). Although Hecht

(1970) detected no significant differences in house fly response to black and white

surfaces across temperatures ranging from 15 to 40°C, he also did not measure the quality

of reflected light.

The spectrum of reflected light, regardless of surface color, is more likely to induce

landing response by house flies than the color of the surface (Bellingham 1995).

Surfaces that reflected UV were more attractive to stable flies, while surfaces that

absorbed UV were more attractive to horse flies (Agee et al. 1983, Hribar et al. 1991).

Colorimetric studies with the face fly, Musca autumnalis, suggested that edge effects of

baited traps could be enhanced by maximizing color contrast between traps and the

surrounding environment (Pickens 1990).

Surfaces

Plane geometric patterns or shapes displayed on a surface may also enhance

landing-response by M. domestica. Single shapes consisting of a large area and perimeter

were significantly more attractive than a series of small shapes with small perimeters

(Bellingham 1995). When house flies were presented with a series layout of squares,

they significantly preferred outer squares and edges versus inner squares, with both sexes

exhibiting significant preference toward shape corners (Bellingham 1995). There were

no significant preferences by house flies toward symmetric versus asymmetric shapes,

but simple shapes such as triangles and rectangles were significantly more attractive to

house flies than complex shapes such as hexagons and octagons (Bellingham 1995).

Bellingham (1995) and Hecht (1970) observed that house flies preferred to rest on rough

dark surfaces such as red and black and preferred matte surfaces over glossy surfaces.

11

Overall, house flies preferred to rest on corners and edges of shapes or objects as well as

narrow vertical objects hanging from ceiling, but they exhibited no significant preference

toward horizontal or vertical stripes on a glue board (Keiding 1965, Bellingham 1995,

Chapman et al. 1999). Later experiments on landing response demonstrated that house

flies significantly preferred a clumped distribution of small black spots against a white

background versus a regular distribution of spots (Chapman et al. 1998, Chapman et al.

1999). These studies suggested that visual cues resembling house-fly aggregations may

also induce landing response (Chapman et al. 1999).

Light

The house fly eye is composed of different cells that are capable of gathering

information about light quantity, quality, and polarization within the surrounding

environment. Each facet of the compound eye of M. domestica contains three different

kinds of photocells designated as R1 – R6, R7, and R8 (McCann and Arnett 1972). Each

cell type provides specific visual information to the insect (McCann and Arnett 1972).

Cells R1- R6 + R7 contain photopigments sensitive to 350-nm and 490-nm peaks with

R8 containing photopigment sensitive to 490 only (McCann and Arnett 1972, Bellingham

1995). The dorsal rim area of the house fly eye detects polarization and polarization

sensitivity is located in the R7 and R8 marginal cells (Philipsborn and Labhart 1990).

Philipsborn and Labhart (1990) determined that house fly attraction to polarized light,

especially in the UV range, is directly related to intensity of light. However, polarized

UV did not always elicit phototactic response from house flies (Philipsborn and Labhart

1990). Polarization sensitivity is thought to provide information on spatial forms,

motions, velocity, and contrast ratio in the fly’s environment and thus may help the fly

track mates (McCann and Arnett 1972, Bellingham 1995).

12

The visible spectrum for M. domestica ranges 310 nm – 630 nm, with optimal

attraction observed at 350 nm (Thimijan and Pickens 1973, Bellingham 1995).

Electroretinogram studies have shown that the M. domestica eye is sensitive to UV light

ranging from 340 nm to 370 nm and blue-green light ranging from 480 nm to 510 nm, but

there is debate over how this sensitivity affects optomotor response of M. domstica

(Goldsmith and Fernandez 1968, McCann and Arnett 1972, Thimijan and Pickens 1973).

Goldsmith and Fernandez (1968) observed positive phototaxis by M. domestica towards

UV light of 365 nm. McCann and Arnett (1972) observed that M. domestica is equally

sensitive to 350 nm UV and 480 nm blue-green and concluded the house-fly eye

contained separate photopigments for UV and blue-green light sensitivity. Similar

studies with the face fly, Musca autumnalis, revealed a similar spectral range from 350

nm to 625 nm with peak sensitivities at 360 nm and 490 nm (Agee and Patterson 1983).

Although blue-green sensitivity was relatively high, M. domestica attraction gradually

decreased from 390 nm to 630 nm with no significant differences between male and

female responses (Thimijan and Pickens 1973). Further studies have shown the house fly

eye contains more UV-sensitive pigments in its dorsal region (Bellingham 1995). It was

hypothesized that sensitivity to UV and blue green light may allow the fly to distinguish

between ground and sky and detect predators or mates against the sky (Bellingham 1995).

Green and red light wavelengths may induce negative phototaxis in M. domestica

(Green 1984). Green (1984) observed a direct relationship between attraction and

intensity of near-UV 400-nm light and an inverse relationship between attraction and

intensity of 550-nm (green) light. Straight UV elicited a significantly stronger

phototactic response from M. domestica than green-UV suggesting that green-UV is less

13

attractive to house flies (Green 1984). Musca domestica were unable to distinguish red

lights from green lights at various intensities (Green 1984). Bellingham (1995) observed

that house flies detected red light (630 nm) but sensitivity to red was not attraction.

Female house flies were more sensitive to red than males with the dorsal region of the

eye containing red-sensitive pigments (Bellingham 1995).

Control Using Attractants

Chemical Baits

Insecticidal food baits or containment traps rely on synthetic attractants such as

muscalure ((Z)-9-tricosene) to attract house flies and provide localized control of house

fly populations. High doses of muscalure mixed with a sugar bait attracted significant

numbers of house flies and seemed to promote significantly higher consumption of

insecticide baits (Morgan et al. 1974, Lemke et al. 1990). Newer technology

incorporating polymer beads impregnated with (Z)-9-tricosene significantly enhanced the

long-term efficacy of sugar baits (Chapman et al. 1998). Physical traps combining

muscalure with visual cues caught significantly more house flies than traps without

muscalure (Mitchell et al. 1975, Mulla et al. 1979). However, baited trap catch decreased

significantly at lower temperatures due to decreased volatilization of attractants (Pickens

and Miller 1987).

Physical Traps

Baited jug traps made from plastic milk jugs, utilized (Z)-9-tricosene and indole to

capture house flies breeding in poultry units (Burg and Axtell 1984). Although this

design killed thousands of house flies, jug traps are primarily used for monitoring house

fly populations (Burg and Axtell 1984, Stafford III et al. 1988).

14

Pickens and Miller (1987) reported that pyramid traps, utilizing glue boards or

electric grids, were effective at intercepting dispersing house flies before they entered

buildings (Pickens and Miller 1987). Subsequent trials with pyramid traps determined

that vertical orientation of electric grids combined with chrome plating on electronic

grids attracted and killed significantly more house flies (Pickens and Mills 1993).

Replacing paint with white plastic increased UV reflectance, and thus attracted

significantly more house flies toward pyramid traps (Pickens and Mills 1993).

Success of physical traps is largely dependent on their proximity to house fly

breeding sites. Baited jug traps were most effective when hung 1 m above breeding and

aggregation sites (Burg and Axtell 1984). Pyramid and baited traps were significantly

more effective when placed within 3 m of breeding sites or sheltered from wind (Pickens

and Miller 1987).

Insect Light Traps (ILT)

Insect light traps (ILTs) and electronic fly killers (EFKs) utilize UV light to lure M.

domestica onto glue boards or kill them with electricity. Such devices are designed to

exploit positive phototaxis in house flies and remove them from environments where

insecticide applications are not an option. However, house fly response to UV traps

varies due to a range of environmental and physiological factors.

House Fly Response to ILTs

Age of M. domestica may influence their response to light traps. Adult male and

female house flies aged 7 d or older exhibited significantly slower response to UV light

traps than flies aged 1 to 5 days (Pickens et al. 1969, Skovmand and Mourier 1986).

Deimel and Kral (1992) observed that light sensitivity was related to age-dependent

concentration of the photopigment xanthopsin in cells R1-R6. Age-dependent sensitivity

15

to light may have been influenced by visual experience gained within the first five days

after adult emergence (Deimel and Kral 1992).

Hunger and nutrition also influenced searching activity of M. domestica, and thus

light-trap catch may also be affected (Skovmand and Mourier 1986). House flies that

were starved or sustained on a sugar and water diet were significantly more active than

protein-satiated flies and thus starved flies responded to UV-light traps in significantly

less time than protein-satiated flies (Skovmand and Mourier 1986). Bellingham (1995)

suggested that food searching is non-oriented behavior motivated by the insect’s intrinsic

nutritional needs. Once the insect satiates its hunger, then its behavior shifts toward mate

location and environmental orientation (Bellingham 1995). This reasoning suggests that

starved house flies are not necessarily more attracted to UV-light traps than satiated flies,

but rather they have a higher probability of being caught simply because they are more

active.

Design and Location of ILTs

Further attempts to enhance ILT performance focused on trap designs included

increasing bulb wattage, manipulating trap colors, and adding reflective surfaces to the

trap exterior. Increased bulb wattage provided a higher intensity of UV light, and thus

yielded a significant increase in catch, but the use of black light blue (BLB) bulbs did not

significantly increase attraction of house or stable flies when compared to standard black

light (BL) bulbs (Pickens 1989b, Snell 1998). Pickens and Thimijan (1986) suggested a

black-box trap offered greatest contrast to UV bulbs and caught significantly more flies.

However, Snell (1998) found that black background was significantly less attractive than

white background. Snell (1998) also suggested that grills created a significant distraction

for house flies by providing them with a place to rest. Traps with greater grill lengths in

16

front of the UV bulbs caught significantly fewer flies compared with traps that had lower

grill length (Snell 1998).

Location of light traps also plays an important role in their efficacy. Studies with

electronic fly killers (EFKs) in poultry units demonstrated that traps located within 1m of

the ground eliminated significantly more house flies than traps located 2m or higher

(Driggers 1971). Subsequent studies with baited pheromone traps also reinforced the

idea that ground-level traps within 3m of breeding sites were most efficient for

eliminating flies (Mitchell et al. 1975, Pickens and Miller 1987). Skovmand and Mourier

(1986) acknowledged that competing light sources as well as competing attractants

distracted a significant number of house flies away from EFKs. They concluded UV-

light traps, specifically EFKs, only provided marginal control in swine units because the

abundance and production of house flies exceeded the traps’ ability to recruit flies

(Skovmand and Mourier 1986).

Competing Light Sources

The urban environment presents house flies with location challenges as well as

artificial light sources that may interfere with UV light traps. Lillie and Goddard (1987)

demonstrated that multiple light traps significantly reduced house fly populations in

restaurant kitchens. However, traps visible to the outdoors may attract flies into the

structure (Lillie and Goddard 1987). Additionally, placement of light traps in dim areas

enhanced the catch of house flies (Pickens and Thimijan 1986). Both Pickens and

Thimijan (1986) and Shields (1989) implied that artificial cool-white fluorescent light

adversely affected house-fly attraction to UV light traps, but neither study examined

intensity or quality of artificial light.

17

Although greater light intensity may attract more flies, other factors such as flicker

fusion and directionality of light may influence house fly response to a light source.

Syms and Goodman (1987) discovered that light flicker created by alternating current

(AC) was more attractive to house flies than light produced by direct current (DC). Ultra

violet lights from AC sources with half the intensity of DC sources caught significantly

more house flies (Syms and Goodman 1987, Shields 1989). Additionally, diffuse sources

of light were significantly more attractive to M. domestica than directional light (Roberts

et al. 1992). Neither Syms and Goodman (1987) nor Roberts et al. (1992) found any sex-

related differences in house-fly response to AC-flicker or diffuse light sources.

The effects of competing light sources on vector monitoring programs utilizing

light traps have been documented in the mosquito literature. Bowden (1973)

acknowledged the inverse relationship between mosquito catch in light traps and intensity

of background illumination from the moon. The intensity of moonlight gradually

changed with each phase, light trap catches of mosquitoes adjusted accordingly (Bowden

1973). In Venezuela, illumination from a full moon reduced light trap catch abundance

of Anopheles spp. by approximately one-half when compared to moonless trap nights

(Rubio-Palis 1992). Similarly in India, Singh et al. (1996) documented significant

reduction of Anopheles spp. caught by Center for Disease Control (CDC) light traps

during a full moon phase compared with moonless trap nights. Although total catch was

significantly lower, the parity rates of Anopheles spp. among samples remained the same

regardless of the moon phase (Rubio-Palis 1992, Singh et al. 1996).

Bowden (1973) documented an inverse relationship between moonlight and trap

catch for a variety of species of Coleoptera and Lepidoptera. Since light intensity

18

decreases at a rate equal to the inverse square of distance from its source, Bowden (1973)

asserted that light traps exerted a region of influence unique to individual species and that

insects outside of this region of influence would remain unaffected by the light trap.

Therefore, modifications to light trap output or the intensity of competing illumination

would alter a light trap’s area of influence (Bowden and Church 1973, Bowden 1982). In

subsequent studies, Bowden (1982) estimated a minimum 12:1 ratio of background

luminosity to trap luminosity was necessary to have an adverse effect on light trap

performance. Increasing UV output from light traps may overcome some of these

obstacles, but Bowden (1982) also noted a curvilinear relationship between total UV

output and trap catch where significant increases in UV output resulted in marginal or no

increases in trap catch (Bowden 1982). It is not known if the same relationship exists for

house flies.

Statement of Purpose

The purpose of my research is to understand how factors in urban environments

affect the catch efficacy of UV light traps used to manage house flies. I have designed a

light-tunnel bioassay that presents house flies with both a UV light trap and a source of

overhead competing light. Since location of UV traps may influence catch, the first

research chapter (Chapter 2) establishes a baseline study of a light-tunnel bioassay that

does not exhibit location bias. This bioassay was then used to determine effects of house

fly age and gender on trap catch. The time to catch 50% of a population (CT50) was

estimated for house flies to determine the approximate time house flies responded to a

UV trap. Information from these studies helped to eliminate any bias and determine the

proper age range of house flies and length of time for the experiments.

19

Chapter 3 explores how intensity and spectrum of competing light sources affects

house fly response to UV light traps. Light intensities sampled in five local restaurants

and grocery stores provided a baseline range of intensity treatments for my experiments.

For light quality experiments, house flies were presented with competing lights with

spectral outputs ranging from UV light up through warm-white fluorescent.

Finally, Chapter 4 explores whether continuous exposure to artificial light induces

habituation or attraction. If house flies habituate to light after continuous exposure, then I

hypothesize that they would be less attracted to that source of light over time.

20

CHAPTER 2 ESTIMATES OF RESPONSE TIME BY HOUSE FLIES TOWARD UV LIGHT

TRAPS USING LIGHT-TUNNEL BIOASSAY

Introduction

The house fly, Musca domestica L., is a synanthropic filth fly that breeds in

garbage and animal waste (Schoof and Silverly 1954a, Greenberg 1973, Imai 1984,

Graczyk et al. 2001). Larvae develop in manure, and the adults will feed on the larval

substrate (Hogsette 1995). Growing populations of adult house flies are a nuisance to

livestock, poultry, and humans, especially in urban centers adjacent to farming

communities (Hogsette and Farkas 2000). In addition, house flies may also transmit

enteric pathogens such as Shigella spp. and Salmonella spp., which they may acquire

from their breeding sites and transmit to humans (Levine and Levine 1991, Graczyk et al.

2001)

The significance of house flies as disease vectors is enhanced by their capability of

dispersing approximately 30 km from their point of origin (Schoof and Silverly 1954b,

Morris and Hansen 1966). Subsequent studies estimated that flies dispersed an average

of 1 to 4 km over a period of 1 to 5 d in search of suitable breeding sites within rural or

urban areas (Morris and Hansen 1966, Hogsette and Farkas 2000).

As house flies cause problems in structures, light traps were developed as a tool to

intercept house flies by attracting them to UV light and killing them with glue boards or

high-voltage electricity (Pickens et al. 1969, Bowden 1982, Roberts et al. 1992). Prompt

removal of house flies within hospitals, grocery stores, or restaurants is necessary to

21

prevent transmission of diseases among people and food sources (Levine and Levine

1991, Rady et al. 1992, Graczyk et al. 2001).

Insect light traps are used to attract and catch house flies, but factors such as fly

age or trap location within a building may limit trap catch. Dispersal from breeding sites

into structures may take days, and as flies disperse, they age and may exhibit a significant

decline in flight activity (Ragland and Sohal 1973). As house flies enter structures, light

traps obscured from view may have little or no effect on a house-fly infestation and

significant wind or air movement within a building may redirect house flies downwind

away from potential light traps (Lillie and Goddard 1987, Rutz et al. 1988, Geden et al.

1999). Additionally, incident light from windows or overhead fixtures may also be an

additional source of variability for light trap studies (Pickens and Thimijan 1986, Syms

and Goodman 1987).

Although previous studies sought to understand variables that may affect light-trap

performance, none have provided a standardized bioassay that eliminates variables such

as background light, trap location, or air movement within a structure. Therefore, the

first objective of this study was to develop and standardize a procedure that overcomes

effects associated with light-trap placement. The second objective was to use the

standardized procedure to examine the effects of fly age on light-trap catch efficacy and

to examine house fly response time to insect light traps.

Materials and Methods

Insects. Two strains of M. domestica were used in this research; the USDA-

CMAVE strain and the Horse-Teaching-Unit (HTU) strain, both from Gainesville, FL.

Larvae from USDA-CMAVE strain were reared on USDA larval medium and held on a

12:12 (L: D) photoperiod (Hogsette 1992). Larvae from the HTU strain were reared on a

22

medium containing 3 liters wheat bran, 1.5 liters water, and 250 ml of Calf Manna®

(Manna Pro Corp., St. Louis, MO) pellets. All stages of HTU strain were placed on a

12:12 (L: D) photoperiod at 26 ± 1°C and 51.03 ± 3.49% RH. Adult flies from both

strains were provided granulated sugar, powdered milk, and water ad libitum and held on

a 12:12 photoperiod (L:D) (Hogsette et al. 2002). Adult flies were held no longer than 7

days.

Before experimentation, adult flies between 2 and 5 d of age were aspirated from

screen cages (25.4 by 53.3 by 26.7 cm) using a handheld vacuum with modified crevice

tool. Aspirated flies were transferred into a refrigerator (~5°C) for 2 min to subdue

activity. Flies were removed from the refrigerator and placed on a chilled aluminum tray,

counted and sexed. Counted and sexed flies were placed into plastic cups (237 ml), lids

were placed over the cups, then the flies were held at room temperature for

approximately 30 min before being placed into experiments. All flies were handled with

camel hair paint brushes and featherweight forceps.

Light tunnel design. The enclosed light-tunnel (152 by 20 dia. cm metal duct)

consisted of a release cage attached to a galvanized aluminum light tunnel that terminated

in a box enclosing a light trap (Fig. 2-1). The release cage (30 by 30 by 45 cm) was fitted

with a sheet-metal bottom and aluminum window screen on the top, sides, and one end.

Stockinette was fitted on the remaining end (30 by 30 cm) to allow access into the cage.

Release cages were placed on a 10.4 cm-high platform to make them level with a light

tunnel entrance. The light tunnel (152 by 20 dia. cm metal duct) was painted with one

coat of primer and one coat of flat black paint, then allowed to cure for at least 3 d to

eliminate paint fumes. A light-tunnel entrance (20 cm dia.) was cut into the box

23

enclosure (66 by 91 by 60 cm) which was constructed of corrugated cardboard. The 20

cm hole was centered horizontally on the 91-cm face and was 12.7 cm from ground level.

Vents were cut in the top of the box enclosure (17.7 by 38.1 cm) to prevent buildup of

heat from light traps. A piece of black organdy was glued over each vent to prevent flies

from escaping. A piece of plywood (91 by 60 cm) was painted with white paint and

placed inside the box enclosure opposite the light tunnel entrance. One UV light trap

(Nova®, Whitmire Microgen Inc., St. Louis, MO) was mounted with four screws onto the

white plywood inside the box enclosure. The trap was laterally centered and located

directly opposite the light tunnel entrance. The trap utilized three 15-watt UV bulbs

(Sylvania® Quantum™, Manchester, UK) as well as a horizontal (7.6 by 40.6 cm) and a

vertical glue board (25.4 by 40.6 cm). Ultra-violet (UV) bulbs in traps had < 1000 h use.

A workshop fixture containing two 40-watt Sylvania® cool-white fluorescent light bulbs

was hung 8 cm above top of release cages to provide a source of background light that is

common in urban environments. The distance of 8 cm above the cages was selected in

order to establish intensity comparable with levels of competing light in urban

environments.

Procedure. To perform an experiment, new glue boards were placed inside traps

and all lights were turned on. One hundred sexed flies were released from a plastic cup

(237 ml) into a release cage. Experiments commenced when stockinette on the release

cages was unfurled and wrapped around the entrance of the light tunnel, allowing flies

access to the UV light trap. At the end of each experiment, the release cages were sealed

and removed, traps turned off, and glue boards collected. Flies not captured were

24

removed from the experimental set up prior to subsequent repetitions. Ambient

temperature for all experiments was approximately 29°C.

Quality and quantity of background light and ultraviolet light were measured at the

release-cage end of the light tunnel with a USB2000® Spectrometer (Ocean Optics®,

Dunedin, FL) (Fig.2-2). Absolute light quantity from cool-white fluorescent light and

UV-trap output was measured with a HOBO® Light Intensity logger (Onset®, Bourne,

MA).

Intensity data from light traps and overhead fluorescent light were analyzed at each

position to investigate significant differences among the light sources. Separate one-way

analyses of variance were run using light intensity as the response variable against trap

and position within building as main factors.

Location dependent assay. Experiments were conducted in two buildings (3 by 3

m) designated as Buildings A and B. All windows were covered with aluminum foil to

prevent external light from interfering with experiments. Two positions were identified

within each building and designated as positions a1 and a2 for Building A and positions

b1 and b2 for Building B. The four box enclosures opposite the release cages were

consecutively numbered and rotated among all four possible positions nested within the

two buildings. All repetitions used house flies from both strains. Four replications, each

with 100 adult house flies (50 M: 50 F) aged 2 to 5 d, were conducted per box and

position, for a total of eight replications per building. Assays were concluded after 4 h.

Age dependent assay. Pupae from both strains were removed from larval medium

and placed in separate screen cages (40.6 by 26.7 by 26.7 cm). Flies were allowed to

emerge for 24 h, then pupae were removed to ensure that all flies were of the same age.

25

Age of flies was based on the number of days after adult emergence from pupal cases.

The assay was conducted with 100 flies (50 M: 50 F) aged 1, 3, 5, or 7 d placed in the

release cage and left for 4 h. Flies on glue boards were counted sexed. Four replications

per age were conducted.

Time dependent assay. Time treatments were started simultaneously when 100

adult flies (50 M: 50 F) were placed into each of four separate release cages for 1, 2, 4, or

8 h. Treatments were randomly assigned to each release cage a priori with four

replications per time. At the end of each time period, the assigned release cage was

closed, glue boards were collected, and the light trap was turned off.

Statistical analysis. For location studies, total numbers of male and female flies

caught on glue boards were analyzed using a two-way nested analysis of variance with

box enclosure and building as fixed factors with position nested within the building.

Time and age studies were separately analyzed with one-way analysis of variance with

time (h) or age (d) as fixed factors. Means separation for significant F-values was

performed with a Student-Newman Keuls (SNK) test. A catch time for 50, 90, and 95%

of house flies (CT50) caught by UV light traps was estimated using probit analysis (SAS

2001).

Results and Discussion

Location Dependent Assay. Analyses of spectrometry data indicated there were

no significant differences in light spectra and intensity from UV light traps (F=0.29; df =

3, 298; P = 0.83) or overhead cool-white fluorescent light among the four set ups

(F=2.22; df = 3, 325; P = 0.085) (Figures 2-2 and 2-3). There were no significant

differences in the numbers of house flies caught among the locations within buildings A

and B (F = 0.89; df = 3, 13; P = 0.46) nor were any significant differences detected

26

among the four box enclosures (F=0.22; df = 3, 13; P = 0.87) (Table 2-1). On average,

65 adult house flies were caught among all positions over a period of 4 h, thus the

different positions within and among buildings A and B did not significantly influence

house fly response to light traps (Table 2-1).

In previous studies, the effects of location bias on catch efficacy of UV light traps

depend largely on environmental factors unique to each site. Lillie and Goddard (1987)

found that catch efficacy in urban environments varied due to trap location relative to

other sources of light such as windows or doors that might lure flies away from a UV

light trap. Light quality and intensity were standardized in this research among all

positions within our buildings. Rutz et al. (1988) suggested that UV light traps are most

effective when placed in close proximity to house-fly breeding sites and areas of high

activity, but they did not define any specific distance. In the current study, house flies

were released 2.66 m from the UV light traps. Furthermore, Geden et al. (1999) reported

that in closed poultry units, house flies significantly preferred dead-air spaces versus

direct air currents. By providing an enclosed light-tunnel design, the current study

eliminated air movement between the release cage and the light trap. Thus, results

showed that removing variability of location, trap distance, background light intensity,

and air movement, assured that the house flies responded to light traps in consistent

manner.

Age-dependent assay. Significantly greater numbers of male house flies aged 1, 3,

and 5 d were caught by UV light traps than 7-day old male house flies (Table 2-2). One

possible reason for this decline is that as male house flies age, wing function declined due

to damage caused by mating attempts (Ragland and Sohal 1973). Within our colonies, I

27

observed mating attempts among flies of all ages but noticed significant wing damage

among males aged 7 d or older.

There was no significant difference in response among all age groups of female

house flies toward UV light traps (Table 2-2). The nutritional state of 7 d old female

house flies may have influenced their activity levels. All house flies had access to protein

(powdered milk), carbohydrates (granulated sugar), and water within 1 h prior to

experiments. Tsutsumi (1968) reported that protein-satiated house flies rest more and fly

less than protein-starved house flies. However, if protein-satiated adult females were

mated, then their flight activity may have increased as they searched for a site for

oviposition (Tsutsumi 1968, Skovmand and Mourier 1986). If females were gravid and

looking for a dark place to oviposit, then one would expect to see a decline in their

response towards light traps.

When results of both sexes were combined, the overall response to UV light traps

by adult house flies significantly decreased at 7 d of age because of the reduction in the

number of males captured (Table 2-2). Results agree with previous studies indicating

that significantly fewer house flies aged > 5 d were caught in UV light traps (Pickens et

al. 1969). As house flies age, their sensitivity to light decreases due to deterioration of

photopigments within cells R1-R6 of the fly eye (Deimel and Kral 1992). These results

confirmed that house flies aged ≤ 5 d are most likely to be caught in UV light traps.

Time-dependent assay. The cumulative mean number of male and female house

flies caught by UV light traps significantly increased over a time period of 1 to 8 h (Table

2-3). Although total trap catch by 8 h was significantly greater than catch at 4, 2, or 1 h,

28

some house flies did not respond to the light trap and remained in the release cage

throughout the duration of the experiment (Table 2-3).

Male house flies were caught inside the light traps within an estimated CT50 of 1.56

h (99 min) (Table 2-4). The CT90 and CT95 estimated catch time for males at 5.03 h

(301.8 min) and 7.01 h (420.6 min), respectively (Table 2-4). Female house flies were

caught inside the light traps within an estimated CT50 of 1.90 h (114 min) (Table 2-4).

The CT90 and CT95 estimated catch time for females at 7.02 h (421.2 min) and 10.17 h

(610.2 min) respectively (Table 2-4).

Probit analysis estimated the CT50 for total house fly response toward an UV light

trap at approximately 1.72 h (103.2 min) (Table 2-4). The CT90 and CT95 estimate for

total house fly catch was 6.01 h (360.6 min) and 8.57 h (514.2 min), respectively (Table

2-4). There was no significant difference between male and female response time as

evident by overlapping 95% confidence intervals for CT50, CT90, and CT95 (Table 2-4).

Skovmand and Mourier (1986), who also conducted a series of light-trap

experiments inside an enclosed chamber, concluded that male house flies responded to

UV light traps in significantly less time than females. The CT50 estimate of 99 min (1.56

h) for male response was similar to their estimated LT50 of 100 min (Skovmand and

Mourier 1986). However, the CT50 estimates for females of 114 min was slower than the

52 min reported by Skovmand and Mourier (1986), and there were no significant

differences in response time between males and females (Table 2-4). During these

studies, I observed some house flies remained inside the release cage throughout the

duration of the test and thus, reduced our estimates for house fly response to light traps.

29

In conclusion, the light-tunnel bioassay enabled us to standardize conditions for age

and time studies by reducing variability associated with air movement, trap location, trap

distance, and background light. House flies that were ≤ 5 d old exhibited significantly

greater attraction toward UV light traps than older flies. Estimates of CT50 by house flies

toward UV traps ranged from 99 to 114 min for males and females, respectively, with no

significant difference in response between the sexes.

30

Table 2-1. Effect of building, position within building, and box enclosure on the number of house flies caught in UV light traps (50 M: 50 F per repetition).

Building Mean ± SE Position Mean ± SE Box enclosure Mean ± SE A 63.56 ± 2.41 a1 63.75 ± 3.79 1 65.62 ± 3.56 B 68.00 ± 2.58 a2 64.87 ± 3.63 2 65.62 ± 3.71 b1 68.37 ± 3.72 3 68.00 ± 3.51 b2 68.12 ± 3.71 4 65.87 ± 4.25 Means within a column followed by the same letter are not significantly different (P = 0.05, Student Newman-Keuls test [SAS Institute, 2001]).

31

Table 2-2. Influence of age and sex on number of house flies caught in UV light traps (50 M: 50 F per repetition)

Fly age (d) 1 3 5 7

Gender Mean ± SE Mean ± SE Mean ± SE Mean ± SE

Male 40.75 ± 2.33a 38.25 ± 1.47a 45.5 ± 1.97a 22.75 ± 3.22b Female 46.25 ± 2.18a 48.25 ± 3.75a 42.5 ± 2.52a 40.00 ± 1.08a Total 87.0 ± 3.21a 87.25 ± 3.37a 88.0 ± 2.67a 62.6 ± 4.21b

Means within a row followed by the same letter are not significantly different (P = 0.05, Student Newman-Keuls test [SAS Institute, 2001]).

32

Table 2-3. Cumulative house-fly catch in UV light traps over time (50 M: 50 F per repetition)

Time (h) 1 2 4 8

Gender Mean ± SE Mean ± SE Mean ± SE Mean ± SE

Male 15.2 ± 1.88a 31.0 ± 1.92b 37.0 ± 2.24b 48.0 ± 1.3c Female 12.6 ± 1.03a 26.8 ± 3.76b 32.8 ± 3.92c 45.8 ± 1.46d Total 27.8 ± 2.6a 57.8 ± 5.32b 71.8 ± 6.58c 93.8 ± 2.03d

Means within a row followed by the same letter are not significantly different (P = 0.05, Student Newman-Keuls test [SAS Institute, 2001]).

33

Table 2-4. Estimated time (h) to catch of adult house flies by UV light traps using Probit analysis

n Reps Slope ± SE CT50 95% C. I. CT90 95% C. I. CT95 95% C. I. X2 P Male 50 5 2.52 ± 0.18 1.56 1.40-1.72 5.03 4.29-6.15 7.01 5.78-9.01 0.34 0.557 Female 50 5 2.26 ± 0.15 1.90 1.71-2.11 7.02 5.88-8.80 10.17 8.19-13.43 0.52 0.467 Total 100 5 2.35 ± 0.11 1.72 0.59-1.84 6.01 5.31-6.95 8.57 7.37-10.26 1.03 0.307

Figure 2-1. Light tunnel design illustrating release cage (30 by 30 by 45 cm)

(foreground), overhead light source (101.6 cm), light tunnel (152 by 20 cm), and box enclosure (66 by 91 by 60 cm) containing light trap

Box Enclosure

Light Tunnel

Release Cage

Overhead Light Source

Platform

35

Figure 2-2. Intensity (lumens / m2) of UV-light trap with relative intensity of light by

wavelength

Intensity ± SE of UV light traps 1.33 ± 0.048 lumens/m2

36

Figure 2-3. Intensity (lumens/m2) of cool-white fluorescent light with relative intensity

of light by wavelength

Intensity ± SE of cool white fluorescent light 54.87 ± 0.92 lumens/m2

37

CHAPTER 3 INFLUENCES OF QUALITY AND INTENSITY OF BACKGROUND LIGHT ON

HOUSE FLY RESPONSE TO LIGHT TRAPS

Introduction

Musca domestica L. is a synanthropic insect that breeds in animal waste,

dumpsters, and garbage (Morris and Hansen 1966, Imai 1984). They are known to

transmit pathogens such as Salmonella spp., Shigella spp., Campylobacter spp., and

enterohemorrhagic E. coli from their breeding sites to open food markets, hospitals,

slaughter houses, and animal farms (Levine and Levine 1991, Iwasa et al. 1999, Graczyk

et al. 2001). Because house flies are potential disease vectors, their control in urban

environments is necessary to prevent food contamination.

A variety of devices have been developed to attract and kill house flies in

agricultural and urban areas. Baited traps containing molasses, sugar, decomposing

biomass, or animal excrement have been used to lure house flies into a catch basin from

which they can not escape (West 1951, Pickens et al. 1973, Mulla et al. 1977). Pyramid

traps utilizing glue boards or electrocution grids were effective at intercepting house flies

before they entered buildings (Pickens and Miller 1987). But although these traps may

be effective in outdoor settings, their odorous baits and visibility prohibit their use

indoors. Additionally, trapped flies must be emptied and baits must be replenished to

maintain trap efficacy.

Insect light traps utilizing ultraviolet (UV) light ranging from 340-370 nm were

developed after physiological and behavior studies demonstrated that house flies

38

exhibited positive phototaxis toward UV-emitting light sources (Goldsmith and

Fernandez 1968, McCann and Arnett 1972). Light traps utilizing glue boards to subdue

attracted flies are a common management tool in indoor settings (Lillie and Goddard

1987).

Ultraviolet light traps for indoor use are an alternative to chemicals, but some

factors in urban environments that may limit trap success. As house flies disperse within

a building, they may encounter competing sources of light originating from windows or

overhead light fixtures which may interfere with trap catch (Pickens and Thimijan 1986).

Previous studies demonstrated that increasing UV output of light traps significantly

enhanced catch efficacy of house flies, but they did not take into account light-trap

performance relative to competing light sources in the urban environment (Pickens and

Thimijan 1986, Snell 1998). Therefore, the first objective of this study was to examine

competing light intensities in public settings where light traps would most likely be used,

then corroborate those data with light-intensity levels in experiments to measure effects

of competing light intensity on house-fly response to UV light traps. The second

objective was to present house flies with competing light sources with different spectral

outputs and quantify their response to UV light traps.

Materials and Methods

Insects. The Horse-Teaching-Unit (HTU) strain of M. domestica from Gainesville,

FL, was used in this research. Larvae from the HTU strain were reared on a medium

containing 3 liters wheat bran, 1.5 liters water, and 250 ml of Calf Manna® (Manna Pro

Corp., St. Louis, MO) pellets. All stages of HTU strain were placed on a 12:12 (L: D)

photoperiod at 26 ± 1°C and 51.03 ± 3.49% RH. Adult flies from both strains were

39

provided granulated sugar, powdered milk, and water ad libitum and held on a 12:12

photoperiod (L:D) (Hogsette et al. 2002). Adult flies were held no longer than 7 days.

Before experimentation, adult flies were aspirated from screen cages (25.4 by 53.3

by 26.7 cm) using a handheld vacuum with modified crevice tool. Aspirated flies were

transferred into a refrigerator (~5°C) for 2 min to subdue activity. Flies were removed

from the refrigerator and placed on a chilled aluminum tray, counted and sexed. Counted

and sexed flies were placed into plastic cups (237 ml), clear plastic lids were placed over

the cups, then the flies were held at room temperature for approximately 30 min before

being placed into experiments. All flies were handled with camel hair paint brushes and

featherweight forceps.

Light tunnel design. Enclosed light-tunnel design consists of a release cage

attached to a galvanized aluminum light tunnel that terminates in a box enclosing a light

trap (Fig. 2-1). The release cage (30 by 30 by 45 cm) was fitted with a sheet-metal

bottom and aluminum window screen on the top, sides, and one end. Stockinette was

fitted on the remaining end (30 by 30 cm) to allow access into the cage. Release cages

were placed on a 10.4 cm-high platform to make them level with a light tunnel entrance.

The light tunnel (152 by 20 dia. cm metal duct) was painted with one coat of primer and

one coat of flat black paint, then allowed to cure for at least 3 d to eliminate paint fumes.

A light-tunnel entrance (20 cm dia.) was cut into the box enclosure (66 by 91 by 60 cm)

that was constructed of corrugated cardboard. The 20 cm hole was centered horizontally

on the 91-cm face, and was 12.7 cm from ground level. Vents were cut in the top of the

box enclosure (17.7 by 38.1 cm) to prevent buildup of heat from light traps. A piece of

black organdy was glued over each vent to prevent flies from escaping. A piece of

40

plywood (91 by 60 cm) was painted with white paint and placed inside the box enclosure

opposite the light tunnel entrance. One UV light trap (Nova®, Whitmire Microgen Inc.,

St. Louis, MO) was mounted with four screws onto the white plywood inside the box

enclosure. The trap was laterally centered and located directly opposite the light tunnel

entrance. The trap utilized three 15-watt UV bulbs (Sylvania® Quantum™, Manchester,

UK) as well as a horizontal (7.6 by 40.6 cm) and a vertical glue board (25.4 by 40.6 cm).

Ultra-violet (UV) bulbs in traps had < 1000 h use. A workshop fixture containing two

40-watt Sylvania® cool-white fluorescent light bulbs was hung 8 cm above release cages

to provide a source of background light that is a common light source in urban

environments. The distance of 8 cm above the cages was selected in order to establish

intensity comparable with levels of competing light in urban environments.

Procedure. To perform an experiment, new glue boards were placed inside traps

and all lights were turned on. One hundred sexed flies were released from a plastic cup

(237 ml) into a release cage. Experiments commenced when stockinette on the release

cages was unfurled and wrapped around the entrance of the light tunnel, allowing flies

access to the UV light trap. After 4 h, experiments were shut down and at the end of each

experiment, the release cages were sealed and removed, traps were turned off, and glue

boards were collected. The time period of 4 h was selected because preliminary results

showed between 90 and 100% of flies within dark controls were caught inside UV light

traps after 4 h. Flies not captured were removed from the experimental set up prior to

subsequent repetitions. Ambient temperature for all experiments was approximately 27

to 29°C. All repetitions contained 100 adult house flies (50 M: 50 F) between 2 and 5 d

of age.

41

Light intensity survey of restaurants and grocery stores. A HOBO® Light

Intensity logger (Onset®, Bourne, MA) was used to measure light intensity inside five

restaurants and/or grocery stores. The logger was held 1.3 m from the ground with its

light sensor facing the ceiling and the researcher carried the logger throughout the

establishment in this fashion. Data were collected at 5-s intervals until a minimum of 100

points were collected at each establishment. Direct sunlight was avoided at all locations

because its high intensity may influence average measurements of artificial light.

Impact of competing light intensity on trap catch. Four intensity levels of

competing light were set up based upon the results of the field survey. Two workshop

light fixtures, each containing two fluorescent 40-watt light bulbs, were suspended

directly above the release cages. A range of 1 to 4 40-watt bulbs were illuminated and

provided light intensities ranging from 27 to 125 lumens/m2. Three replications were

conducted per intensity level.

Impact of competing light spectra on trap catch. Four types of fluorescent light

bulbs were presented to house flies as a source of overhead competing light. The bulb

models and types were as follows: Sylvania® Warm White (F40T12/WW), Sylvania®

Cool White (F40T12/CW), Sylvania® Daylight (F40T12/DX), and Sylvania ® Blacklight

(F40T12/350BL). Two fluorescent workshop light fixtures, each capable of holding two

40-watt light bulbs, were suspended directly above the release cages. Three 40-watt

bulbs of each model were placed inside the fixtures and illuminated during experiments.

Four replications were conducted per treatment.

Spectral analyses and relative intensity of all treatments were measured using a

USB2000® spectrometer (Ocean Optics®, Dunedin, FL). Light intensity for all treatment

42

outputs was measured with a HOBO® Light Intensity logger (Onset®, Bourne, MA).

Since measurements of light intensity by HOBO® Light Intensity logger (350 to 700 nm)

represented a proportion of total spectrum measured by the USB2000® spectrometer (200

to 820 nm), total light intensity was estimated using the following formulae where Σ Total

spectrum units represents relative light intensity measured by the USB2000® spectrometer and

Σ Measured light units represents relative light intensity perceived by the HOBO® Light

Intensity logger. Measured light represents the light intensity (lumens/m2) recorded by

the HOBO® Light Intensity logger and units measured represent intensity counts per

nanometer tabulated by USB2000® spectrometer using OOIBase32 software (Ocean

Optics®, Dunedin, FL).

Σ Measured light units

Σ Total spectrum units = Proportion Total light output (%)

Measured light (lumens/m2)

Proportion Total light output (%) = Estimate Total light output (lumens/m2)

Once the Estimate Total light output (lumens/m2) was calculated, the intensity levels of

UV (350 to 370 nm) and blue-green light (480 to 510 nm) were also calculated. The Σ UV

light units and Σ Blue-green light units represent intensity counts per nanometer tabulated by

USB2000® spectrometer using OOIBase32 software (Ocean Optics®, Dunedin, FL).

Σ UV light units

Σ Total spectrum units = Proportion UV light output (%)

Proportion UV light output (%) * Estimate Total light output (lumens/m2)

= Estimate UV light output (lumens/m2)

Σ Blue-green light units

43

Σ Total spectrum units = Proportion Blue-green light output (%)

Proportion Total light output (%) * Estimate Total light output (lumens/m2)

= Estimate Blue-green light output (lumens/m2)

Statistical analysis. Because all four treatments for the light-intensity experiments

and light-quality experiments could not be conducted simultaneously, both experiments

were set up using a two-way balanced incomplete block design. Treatment pairs were

randomly assigned a priori for each trial day until all possible treatment combinations

were met (SAS 2001). A dark control was run concurrently with each experiment. For

each dark control, house flies were placed into a release cage and presented with an

illuminated Whitmire Nova® trap at the end of the light tunnel without a competing light

source placed overhead. Means were separated with a Student Newman-Keuls test.

Regression analysis was conducted on data from light-intensity experiments to examine

the relationship between trap catch and intensity of blue-green light. Another regression

analysis was conducted on light-quality experiments to examine the relationship between

trap catch and UV intensity.

Results and Discussion

Light intensity survey. Results of light-intensity survey at area restaurants and

grocery stores showed intensity of artificial and natural light sources ranged from

approximately 27 to 91 lumens/m2 (Table 3-1). Light intensity of treatments within

laboratory bioassays was within the range of field results (Table 3-2).

Impact of competing light intensity on trap catch. The number of males caught

in UV traps significantly decreased when intensity of the competing light exceeded 91.46

lumens/m2 when compared with dark controls (F= 9.63; df = 4, 50; P < 0.0001) (Table 3-

3). The number of females caught declined significantly when intensity of competing

44

light exceeded 51.43 lumens/m2 (F= 18.17; df = 4, 50; P < 0.0001) (Table 3-3). When

the data were combined, the overall results showed total catch in UV light traps

decreased significantly as the intensity of competing light source increased (F = 39.46; df

= 4, 50; P < 0.0001) (Table 3-3).

As overall competing light intensity was increased, spectral analyses showed the

relative intensity of a blue-green light increased 5x from the lowest to highest treatment

(Table 3-4; Figs. 3-1 to 3-4). Regression analysis showed a significant correlation

between increases in blue-green light and decreases in trap catch (Fig. 3-5). Blue-green

light ranging between 480nm and 510nm constituted approximately 13% of total light

emitted from fluorescent fixtures in all treatments (Table 3-4; Figs. 3-1 to 3-4). Both

Pickens and Thimijan (1986) and Shields (1989) have suggested that artificial cool-white

fluorescent light adversely affected house-fly attraction to UV light traps, but neither

study measured spectral output nor measured their effects on house-fly behavior. The

blue-green light emitted by cool-white fluorescent bulbs in the current study

corresponded directly with the blue-green sensitivity of the house-fly eye demonstrated in

previous studies (Figs. 3-1 to 3-4) (McCann and Arnett 1972, Bellingham 1995). These

results suggest that relatively high intensities of competing light containing blue-green

wavelengths may distract house flies from relatively low intensities of ultraviolet emitted

from light traps.

Approximately 1 to 2% of light emitted from cool-white fluorescent treatments

consisted of UV ranging between 350 to 370 nm (Table 3-4; Figs 3-1 to 3-4). Spectral

analyses showed the UV emission from fluorescent treatments exceeded the UV

originating from light traps by almost 4x when four bulbs were used (Table 3-4; Figs. 3-1

45

to 3-4). However, the spectrum of the UV consisted of a narrow spike that peaked at 365

nm contrasted with the broad-based UV from the light traps ranging from 310 to 399 nm

with a peak at 350 nm (Table 3-4; Figs. 3-1 to 3-4). Previous studies have demonstrated

that higher intensity of UV output significantly increased house fly catch within light

traps (Pickens and Thimijan 1986, Pickens 1989b, Snell 1998). But if house flies in this

study were simply responding to UV intensity, then one would expect to find a greater

number of flies remaining inside the release cage at the conclusion of the experiments.

Bowden and Church’s studies (1973) documented an inverse relationship between

moonlight and trap catch for multiple species of beetles and moths. Since light intensity

decreases at a rate equal to the inverse square of distance from its source, Bowden and

Church (1973) asserted that light traps exerted a region of influence unique to individual

species. Insects outside of this region would remain unaffected by the trap, and

modifications to light-trap output or intensity of competing illumination would alter the

size of this region (Bowden and Church 1973). If the same concept applies to house flies,

then competing fluorescent light originating from multiple overhead light fixtures reduces

the region of influence of UV light traps by saturating the environment with full-

spectrum fluorescent light. Subsequently, Bowden (1982) estimated that a minimum

12:1 ratio of background light to trap light was necessary to have an adverse effect on

light trap performance. This ratio may hold for some species of Coleoptera or

Lepidoptera, but my lab studies found that background light intensity must be

approximately 25 times greater than light intensity from a trap to have a significant

adverse effect on house fly response (Bowden 1982). Although this may seem high,

intensity of competing light in urban environments can meet or exceed light levels

46

reported in this study (Table 3-1). In addition, as the intensity of UV light diminishes

over distance, the survey study showed that average light intensity from competing

sources remained relatively constant within each restaurant or grocery store (Table 3-1).

Impact of competing light spectra on trap catch. Results of the light quality

studies showed significantly fewer male (F = 21.28; df = 4, 64; P < 0.0001) and female

house flies (F = 37.85; df = 4, 64; P < 0.0001) were caught among all treatments when

compared against a dark control (Table 3-5). When the data were pooled together,

overall trap catch among all treatments was also significantly lower than the dark control

(F = 56.60; df = 4, 64; P < 0.0001), but significantly fewer flies were caught in light traps

when competing light consisted of black light versus daylight, cool-white, and warm-

white fluorescent (Tables 3-5 and 3-6; Figs. 3-5 to 3-8).

Blacklight bulbs emitted the lowest intensity of blue-green light while day light

bulbs emitted the highest intensity of blue-green (Table 3-6; Figs. 3-6 to 3-9). For this

study, regression analysis showed a significant correlation between increases in UV and

decreases in trap catch (Fig. 3-10). Intensity of UV emitted from Blacklight treatments

was approximately 10x greater than UV intensity from daylight, cool white, and warm

white treatments (Table 3-6; Figs. 3-6 to 3-9). In addition, the intensity of UV output

from all treatments exceeded UV emitted from light traps (Table 3-6; Figs. 3-6 to 3-9).

Yet the spectrum of the UV produced by daylight, cool white, and warm white

fluorescent bulbs consisted of a narrow spike peaking at 365 nm contrasted with

blacklight treatments and insect light traps which emitted broad-based UV ranging from

310 – 399 nm and peaking at 350 nm (Table 3-6; Figs. 3-6 to 3-9).

47

The M. domestica eye is sensitive to UV light ranging from 340 nm to 370 nm and

blue-green light ranging from 480 nm to 510 nm, but there is debate over how this

sensitivity affects a house fly’s optomotor response (Goldsmith and Fernandez 1968,

McCann and Arnett 1972, Thimijan and Pickens 1973, Green 1984). Although blue-

green sensitivity was relatively high, phototactic response by male and female M.

domestica gradually declined as light spectra approached 630 nm (Thimijan and Pickens

1973). Results from our light quality experiments were consistent with previous

literature indicating that house flies exhibited a stronger response toward UV versus blue-

green wavelengths (Pickens 1989a).

In conclusion, the results of our lab study showed a significant decrease in response

of male and female house flies toward UV light traps as the intensity of competing

fluorescent light was increased. When house flies were presented four different types of

competing light, their response towards UV light traps was significantly lower when

competing light sources contained broad-based UV versus blue-green light.

48

Table 3-1. Light intensity (lumens/m2) measured within five local restaurants (R) and grocery stores (G)

Location n Intensity

A (G) 100 27.33 ± 1.59 B (R) 100 28.29 ± 0.37 C (R) 100 50.67 ± 0.80 D (G) 100 61.43 ± 2.42 E (R) 100 91.24 ± 1.28

Table 3-2. Light intensity (lumens/m2) of four intensity treatments of cool-white

fluorescent light measured 45 cm from light source

Number of bulbs Total wattage Intensity

1 40 W 27.43 2 80 W 51.21 3 120 W 91.46 4 160 W 125.67

49

Table 3-3. Effect of intensity of cool-white fluorescent light as a competing light source on number of adult house flies (mean ± SE) caught in UV light traps (50 M: 50 F per repetition)

Light intensity

Gender Dark control 27.43 51.43 91.46 125.67 Male 45.25 ± 0.51a 42.66 ± 1.31ab 41.88 ±1.16ab 40.00 ± 1.49bc 37.00 ± 1.15c Female 47.00 ± 0.58a 45.00 ± 1.28ab 42.66 ± 0.70bc 40.55 ± 1.37cd 38.22 ±1.35d Total 92.29 ± 0.85a 87.66 ± 1.45b 84.55 ± 1.20b 80.55 ± 0.97c 75.22 ± 0.92d Means within a row with the same letter are not significantly different (P=0.05; Student-Newman Keuls [SAS Institute, 2001])

50

Table 3-4. Estimated intensity (lumens/m2) of total spectral output, blue-green output, and ultraviolet output emitted from competing light sources and light traps used in light quantity experiments

Number of Estimated total Blue-green output UV output Blue-green Total Cool white bulbs light intensity (480-510nm) (350-370nm) + UV output Trap Catch 1 33.01 3.36 0.70 4.06 87.66 ± 1.45 2 59.23 6.46 1.03 7.49 84.55 ± 1.20 3 104.22 11.85 1.26 13.11 80.55 ± 0.97 4 140.60 16.66 1.59 18.65 75.22 ± 0.92 UV Trap 1.95 0.06 0.44 0.50 --

51

Table 3-5. Effect of competing light quality on mean number (± SE) of adult house flies caught in UV light traps (50 M: 50 F per repetition)

Competing light source Gender Dark control Warm white Cool white Daylight Blacklight Male 45.91 ± 0.61a 40.25 ± 1.15b 39.16 ± 1.86b 39.66 ± 0.91b 30.83 ± 1.91c Female 46.71 ± 0.63a 35.66 ± 2.14b 33.16 ± 2.61b 34.50 ± 1.21b 21.08 ± 2.13c Total 92.79 ± 0.81a 75.91 ± 2.72b 73.41 ± 1.87b 74.16 ± 1.63b 52.08 ± 3.84c Means within a row with the same letter are not significantly different (P=0.05; Student-Newman Keuls [SAS Institute, 2001])

52

Table 3-6. Estimated intensity (lumens/m2) of total spectral output, blue-green output, and ultraviolet output emitted from competing light sources and light traps used in light quality experiments

Competing light Estimated total Blue-green output UV output Blue-green Total spectrum light intensity (480-510nm) (350-370nm) + UV output Trap Catch Blacklight 73.84 2.02 15.79 17.81 52.08 ± 3.84 Day Light 76.61 11.94 1.27 13.21 74.16 ± 1.63 Cool White 84.80 9.68 1.30 9.98 73.41 ± 1.87 Warm White 89.62 10.57 1.73 12.30 75.91 ± 2.72 UV Trap 1.95 0.06 0.44 0.50 --

53

Figure 3-1. Spectral analysis and mean intensity (lumens/m2) of 1 Sylvania® Cool White

fluorescent bulb measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Cool White 27.43 lumens/m2

54

Figure 3-2. Spectral analysis and mean intensity (lumens/m2) of 2 Sylvania® Cool White

fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Cool White 51.21 lumens/m2

55

Figure 3-3. Spectral analysis and mean intensity (lumens/m2) of 3 Sylvania® Cool White

fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Cool White 91.46 lumens/m2

56

Figure 3-4. Spectral analysis and mean intensity (lumens/m2) of 4 Sylvania® Cool White

fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Cool White 125.67 lumens/m2

57

y = -0.9108x + 90.723R2 = 0.9933

74

76

78

80

82

84

86

88

90

0 2 4 6 8 10 12 14 16 18

Intensity of Blue-green light (480-510nm)

Trap

cat

ch

Figure 3-5. Regression analysis showing relationship between trap catch and intensity

(lumens/m2) of blue-green light

58

Figure 3-6. Spectral analysis and mean intensity (lumens/m2) of Sylvania® Blacklight

bulbs measured at 61 cm from source. Arrow highlights UV peak between 340 and 370 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Blacklight Bulb 43.46 ± 1.84 lumens/m2

59

Figure 3-7. Spectral analysis and mean intensity (lumens/m2) of Sylvania® Daylight

fluorescent bulbs measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Daylight Bulb 65.9 ± 1.08 lumens/m2

60

Figure 3-8. Spectral analysis and mean intensity (lumens/m2) of Sylvania® Cool White

fluorescent light measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

W avelength (nm)

MasterSylvania® Cool White Bulb 73.81 ± 0.69 lumens/m2

61

Figure 3-9. Spectral analysis and mean intensity (lumens/m2) of Sylvania® Warm White

fluorescent light measured at 61 cm from source. Arrow highlights blue-green peak between 480 and 510 nm.

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterSylvania® Warm White Bulb 74.04 ± 0.59 lumens/m2

62

y = -1.5558x + 76.704R2 = 0.9854

40

45

50

55

60

65

70

75

80

0 5 10 15 20

Intensity of Ultraviolet (350-370nm)

Trap

Cat

ch

Figure 3-10. Regression analysis showing relationship between trap catch and intensity

(lumens/m2) of blue-green light

63

CHAPTER 4 LIGHT TRAP HABITUATION STUDY

Introduction

The house fly Musca domestica (Diptera: Muscidae) is a nuisance in agricultural

and urban environments (Cosse and Baker 1996, Moon 2002, Hogsette 2003). High

populations of house flies can cause economic losses in livestock, and dispersing house

flies are pestiferous in residential and commercial areas (Hogsette and Farkas 2000).

House flies breed in animal waste, dumpsters, and garbage and have been implicated as

mechanical vectors of enteric diseases such as Salmonella spp. and Shigella spp. among

animals and humans (Imai 1984, Graczyk et al. 2001, Mian et al. 2002).

In urban areas, UV light traps are used to manage house flies. Insect light traps that

utilize ultra-violet light were developed as an alternative to insecticide applications. As

house flies enter structures they are exposed to artificial light through time, but it is

unknown whether continued exposure to artificial light influences their sensitivity to UV

light traps. If house flies habituate to background light in their surrounding environment,

then they may be more inclined or disinclined to fly towards a UV-light trap. Therefore,

the objective of this study was to determine if previous experience with fluorescent or

UV light influences house fly response to UV light traps.

Materials and Methods

Insects. The Horse-Teaching Unit (HTU) strain of house fly, M. domestica, from

Gainesville, FL, was used for all studies presented here. Larvae were reared on a

medium containing 3 liters wheat bran, 1.5 liters water, and 250 ml of Calf Manna®

64

(Manna Pro Corp., St. Louis, MO) pellets. All stages of HTU strain were placed on a

12:12 (L: D) photoperiod at 26°C + 1°C and ~55% RH. Adult flies from both strains

were provided granulated sugar, powdered milk, and water ad libitum and held on a

12:12 photoperiod (L:D) (Hogsette 1992, Hogsette et al. 2002). Adult flies were held no

longer than 7 d.

Prior to experimentation, adult flies were aspirated from screen cages using a

handheld vacuum with modified crevice tool to aspirate adult flies. Aspirated flies were

transferred into a refrigerator (~5°C) for 2 min to subdue activity. Subdued flies were

removed from the refrigerator and placed on a chilled aluminum tray, then counted and

sexed. Counted and sexed flies were placed into deli cups (237 ml) and held at room

temperature for approximately 30 min. All flies were handled with camel hair

paintbrushes and featherweight forceps to prevent damage.

Light tunnel design. Enclosed light-tunnel design consisted of a release cage

attached to a galvanized aluminum light tunnel that terminates in a box enclosing a light

trap (Fig. 1). The release cage (30 by 30 by 45 cm) was fitted with a sheet-metal bottom

and aluminum window screen on the top, sides, and one end. Stockinette was fitted on

the remaining end (30 by 30 cm) to allow access into the cage. Release cages were

placed on a 10.4 cm platform to make them level with a light tunnel entrance. The light

tunnel (152 by 20 dia. cm metal duct) was primed and painted with one coat of primer

and one coat of flat black paint, then allowed to cure for at least 3 d to eliminate paint

fumes. A light-tunnel entrance (20 cm dia.) was cut into the box enclosure (66 by 91 by

60 cm) which was constructed of corrugated cardboard. The 20 cm hole was centered

horizontally on 91 cm face, and it was 12.7 cm from ground level. Vents were cut into

65

the top of the box enclosure (17.7 by 38.1 cm) to prevent buildup of heat from light traps.

A piece of black organdy was glued over each vent to prevent flies from escaping. A

piece of plywood (91 by 60 cm) was painted with white paint and placed inside the box

enclosure opposite the light tunnel entrance. One UV light trap (Nova®, Whitmire

Microgen Inc., St. Louis, MO) was mounted with four screws onto the white plywood

inside the box enclosure. The trap was laterally centered and located directly opposite

the light tunnel entrance. The trap utilized three 15-watt UV bulbs (Sylvania®

Quantum™, Manchester, UK) as well as horizontal (7.6 by 40.6 cm) and vertical (25.4 by

40.6 cm) glue boards. Ultra-violet light bulbs in light traps had less than 1000 h use. A

workshop light containing two 40-watt Sylvania® cool-white fluorescent light bulbs was

hung 8 cm above release cages to provide a source of background light that is a common

light source in urban environments.

Procedure. All experiments were conducted inside two buildings (3 by 3 m); each

building held two light tunnels. New glue boards were placed inside traps and all lights

were turned on. One hundred counted and sexed adult flies were released from a plastic

cup (237 ml) into a release cage. Experiments commenced when stockinette on the

release cages was unfurled and wrapped around the entrance of the light tunnel, allowing

access to the UV light trap. At the end of each experiment the release cages were sealed

and removed, traps were turned off and glue boards were collected. Flies not captured

were removed from the experimental set up prior to subsequent repetitions. Ambient

temperature for all experiments was 29°C.

Quality and quantity of light were recorded at the release-cage end of the light

tunnel (Fig. 2). Spectral analyses and relative light intensities were measured using a

66

USB2000® Spectrometer (Ocean Optics®, Dunedin, FL). Absolute light quantity for

cool-white fluorescent light output and UV-trap output was measured with a HOBO®

Light Intensity logger (Onset®, Bourne, MA).

Light habituation treatments. All house flies in primary lab colonies were reared

on a 12:12 (L:D) photoperiod using 4 40-watt GE® Wide Spectrum Plant and Aquarium

bulbs (GE F40PL/AQ) at intensity of 10.28 ± 2.38 lumens/m2. Prior to habituation

experiments, house fly pupae were separated from primary lab colonies, placed in a

screen holding cage (30 by 17.5 by 30 cm) and stored in a separate rearing room.

Holding cages were covered on top and three sides with aluminum foil to prevent

overhead light from entering the cages. The side of the holding cage (30 by 17.5 cm) that

was not covered by aluminum foil was placed 12 cm away directly in front of a light

fixture. Light fixtures provided either cool-white fluorescent light from four 15W

Sylvania® Cool White bulbs or UV light from four 15W Sylvania® Quantum™ Blacklight

bulbs. Cool white fluorescent light was selected for this treatment because it is a

common source of indoor lighting. Emerging adult house flies in holding cages were

reared on a 12:12 photoperiod (L:D) of either cool-white fluorescent light at intensity of

34.11 ± 0.54 lumens/m2 or black light bulbs at intensity of 15.88 ± 0.39 lumens/m2 for 2

to 3 d prior to experiments. All house flies were provided with powdered milk,

granulated sugar, and water ad libitum.

Statistical analysis. Since both treatments for the habituation experiments could

not be conducted simultaneously, this study was set up using a two-way balanced

incomplete block design. Treatment pairs were randomly assigned a priori for each trial

day until all possible treatment combinations were met (SAS 2001). A dark control was

67

run concurrently with each repetition. For each dark control, house flies were placed into

a release cage and presented with an illuminated light trap at the end of the light tunnel

without a competing light source placed overhead. The house flies used in all controls

were selected from the original laboratory colonies. A Whitmire Nova light trap was

used in all dark controls.

Results and Discussion

Although all treatments caught significantly fewer house flies than the dark control,

there was no significant difference in the response to UV light traps among house flies

reared on UV light, cool-white light, versus the plant and aquarium light used in the

laboratory (F = 11.47; df = 3, 21; P < 0.0001) (Table 4-1). Rearing house flies on

blacklight or cool-white fluorescent did not influence their response to UV light traps

(Table 4-1; Figs. 4-1 to 4-3). If house flies did habituate to blacklight, then we would

have expected a significantly lower response to UV light traps. Conversely, if they

habituated to cool-white fluorescent, then we would have expected to see a significant

increase in their response to UV light traps.

Fukushi (1976) demonstrated that house flies could discriminate among narrow

ranges of light wavelengths when specific wavelengths were associated with sugar water.

Although this experiment of classical conditioning was not directly related with my

experiment, it does illustrate that visual experience with specific wavelengths of light can

influence house fly behavior (Fukushi 1976).

Pickens et al. (1969) speculated that adult house flies exposed to UV-light traps for

at least 12 h exhibited a significantly greater response towards light traps compared with

adult house flies that did not have previous visual experience with UV. This result would

suggest that house flies developed increased sensitivity to UV, not habituation (Pickens et

68

al. 1969). But our results showed that that prior exposure to UV light did not significantly

increase or decrease catch efficacy of light traps (Table 4-1). Subsequent studies on

visual sensitivity of house flies showed that dark-reared flies responded to significantly

lower intensity levels of light than house flies reared on a 12:12 (L:D) photoperiod

(Deimel and Kral 1992). Thus, Deimel and Kral (1992) determined that fly vision

developed within the initial 1-5 d after adult emergence and suggested that visual

experience within this time frame may influence the flies’ sensitivity to light. However,

their research did not compare sensitivity across different light spectra, but rather light

intensity needed to stimulate the optic nerve (Deimel and Kral 1992). These results show

that the spectrum of light presented to house flies during this developmental period did

not influence house fly response to overhead or UV light when placed in a bioassay that

provides them with a choice of light spectra.

69

Table 4-1. Mean number of adult house flies caught in UV light traps after being pre-conditioned under different light conditions.

Pre-conditioning light treatments Gender Control Wide spectrum Black light Cool white Male 45.22 ± 0.51a 40.66 ± 1.31b 36.33 ±1.16b 36.66 ± 1.49b Female 44.00 ± 0.58a 41.16 ± 1.28b 40.33 ± 0.70b 40.50 ± 1.37b Total 89.22 ± 0.85a 81.82 ± 2.45b 76.66 ± 1.20b 77.16 ± 1.97b Means within a row with the same letter are not significantly different (P=0.05; Student-Neuman Keuls [SAS Institute, 2001]).

70

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

Master

Figure 4-1. Spectral analysis and mean intensity of GE® Plant & Aquarium fluorescent

light used in house fly rearing room. Mean light intensity presented in lumens/m2.

Rearing Room GE® Plant & Aquarium 10.28 ± 2.38 lumens/m2

71

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

Master

Figure 4-2. Spectral analysis and mean intensity of Sylvania® Blacklight used to rear

treatment house flies. Mean light intensity presented in lumens/m2.

Sylvania® Blacklight 15.88 ± 0.39 lumens/m2

72

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

Master

Figure 4-3. Spectral analysis and mean intensity of Sylvania® Cool White fluorescent

light used to rear treatment house flies. Mean light intensity presented in lumens/m2.

Sylvania® Cool White 34.11 ± 0.54 lumens/m2

73

CHAPTER 5 SUMMARY AND CONCLUSIONS

The main purpose of this research was to investigate factors in the urban

environment that inhibit the catch efficacy of UV light traps used to manage the house

fly, Musca domestica, in urban environments. To do this, the first priority was to develop

a standard bioassay that eliminated or reduced position effects associated with light-trap

placement that influence results. Initial studies with a light tunnel bioassay demonstrated

there were no significant position effects detected among two research buildings, four

positions, or box enclosures which enclosed the light traps. In addition, the light-tunnel

bioassay minimized air movement and standardized trap location, trap distance, and

background light for future experiments.

The first portion of this research investigated the effect of house fly age on its

response to UV light traps. House flies that were 5 d and younger exhibited significantly

greater attraction toward UV light traps than older flies. The second part of the first

research chapter used probit analysis to estimate response time of house flies to UV traps.

A catch time for 50% of house flies (CT50) within UV traps was estimated from 99 – 114

min for males and females. The estimated CT50 for total house fly response toward an

UV light trap was approximately 1.72 h (103.2 min). The CT90 and CT95 estimates for

total house fly catch were 6.01 h (360.6 min) and 8.57 h (514.2 min) respectively. There

was no significant difference between male and female response time as evident by

overlapping 95% confidence intervals for CT50, CT90, and CT95.

74

For the second portion of this research, house flies were presented various intensity

levels of cool-white fluorescent light in order to determine whether intensity of non-UV

competing light sources influenced house fly attraction to UV light traps. Intensity levels

in experiments correlated with preliminary surveys of overhead and natural light within

local grocery stores and restaurants where light traps are commonly used. Results

showed that the number of males caught in UV traps significantly decreased when

intensity of the competing light exceeded 91.43 lumens / m2. Significant declines in

catch of females occurred at a lower intensity when the competing light exceeded 51.43

lumens / m2. When the data were combined, the overall results showed total catch in UV

light traps decreased significantly as the intensity of competing light source increased.

These results demonstrated a significant decrease in response of male and female house

flies toward UV light traps as the intensity of competing fluorescent light was increased.

House flies were also presented with four different types of competing light which

covered a broad spectral range from UV to red (700 nm) which is beyond the house fly’s

visual perception. Again, house fly response toward UV light traps significantly declined

when a source of competing light was introduced. However, house fly response towards

UV light traps was significantly lower when background light contained broad-based UV

versus background light containing blue-green light and no UV.

Finally, the third portion of this research investigated whether or not house flies

habituated to light quality within their surrounding environment. House flies from

current colonies were compared against house flies reared on black light and cool-white

fluorescent light. The results of habituation experiments showed that all treatments

caught significantly fewer house flies than the dark control. However, there was no

75

significant difference in the response to UV light traps among house flies reared on UV

light, cool-white fluorescent light, and grow-lights which are used in the rearing rooms.

The spectrum of light used in rearing did not significantly influence house fly response to

UV light traps. These results also suggest that previous experience to different kinds of

light does not influence house fly response to light traps.

76

APPENDIX A DIAGRAM OF BUILDING LAYOUT

Figure A-1. Diagram of buildings, positions, and bioassay layout at USDA

X X

a1 a2A

1 2

Building

Position

Box Enclosure

Location of Light Measurements

Overhead Fluorescent Light Fixture

Release Cage

X X

b1 b2B

3 4

3 m

3 m

77

APPENDIX B SAS PROGRAMS USED FOR DATA ANALYSIS

SAS programs for Chapter 2

/Analysis of variance for study standardizing the bioassay/ / ‘Position’ is nested within ‘Building’/ Proc glm data = work.fly; Class building (position); Model male fem total = building (position); Means building (position) / snk; Run; /Analysis of variance for age study/ Proc glm data = work.fly; Class age; Model male fem total = age; Means age / snk; Run; /Probit analyses for Time study/ /Probit analysis for total number of flies caught on glue boards/ Proc probit data = work.fly inversecl log10 lackfit; Class gbtot; Model time/n = hrs /; Run; /N = 500/ /Probit analysis for adult male house flies caught on glue boards/ Proc probit data = work.fly inversecl log10 lackfit; Class male; Model time/n1 = hrs /; Run; /N1 = 250/

78

/Probit analysis for adult female house flies caught on glue boards/ Proc probit data = work.fly inversecl log10 lackfit; Class female; Model time/n1 = hrs /; Run; /N1 = 250/ /Analysis of variance comparing light output of four UV light traps/ Proc sort data = work.light; By trap; Proc glm data = work.light; Class trap; Model intensity = trap; Means trap / SNK; Run; /Analysis of variance comparing overhead cool-white fluorescent light measured at four independent positions/ Proc sort data = work.light; By position; Proc glm data = work.light; Class position; Model intensity = position; Means position / SNK; Run;

79

SAS programs for Chapter 3

Proc sort data = work.fly; by day treatmnt; Proc univariate data = work.fly; Class treatmnt; Var total male fem; Run; / Balanced Incomplete Block Design (BIBD); Two-way analysis of variance (BIBD) of light intensity data / Proc sort data = work.fly; by day treatmnt; Proc glm data = work.fly; Class day treatmnt; Model male fem total = day treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc glm data = work.fly; Class day treatmnt; Model armale arfem artotal = day treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc sort data = work.sex; by treatmnt; Proc glm data = work.sex; by treatmnt; Class sex; Model resp aresp = sex; Means sex / snk; Proc sort data = work.sex; by sex; Proc glm data = work.sex; by sex; Class treatmnt; Model resp aresp = treatmnt; Means treatmnt / snk; Run;

80

/Proc univariate for light quality data/ Proc sort data = work.fly; by day treatmnt; Proc univariate data = work.fly; Class treatmnt; Var total male fem; /Balanced Incomplete Block Design; Two-way analysis of variance (BIBD) of light quality data/ Proc sort data = work.fly; by day treatmnt; Proc glm data = work.fly; Class day treatmnt; Model male fem total = day treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc glm data = work.fly; Class day treatmnt; Model armale arfem artotal = rep treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc sort data = work.sex; by treatmnt; Proc glm data = work.sex; by treatmnt; Class sex; Model resp aresp = sex; Means sex / snk; Proc sort data = work.sex; by sex; Proc glm data = work.sex; by sex; Class treatmnt; Model resp aresp = treatmnt; Means treatmnt / snk; Run;

81

SAS Programs for Chapter 4

Proc sort data = work.fly; by day treatmnt; Proc univariate data = work.fly; Class treatmnt; Var total male fem; Run; / Balanced Incomplete Block Design (BIBD); Two-way analysis of variance (BIBD) for light habituation data/ Proc sort data = work.fly; by day treatmnt; Proc glm data = work.fly; Class rep treatmnt; Model male fem total = day treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc glm data = work.fly; Class day treatmnt; Model armale arfem artotal = day treatmnt; Means treatmnt / snk; Lsmeans treatmnt / pdiff; Proc sort data = work.sex; by treatmnt; Proc glm data = work.sex; by treatmnt; Class sex; Model resp aresp = sex; Means sex / snk; Proc sort data = work.sex; by sex; Proc glm data = work.sex; by sex; Class treatmnt; Model resp aresp = treatmnt; Means treatmnt / snk; Run;

82

APPENDIX C SPECTROMETRY MEASUREMENTS FOR LIGHT TRAPS AND BACKGROUND

LIGHT

Figure C-1. Spectral analysis and mean light intensity of Whitmire Nova trap 1 at

Position a1

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition a1 Trap 1

Mean light intensity 1.33 ± 0.15 lumens/m2

83

Figure C-2. Spectral analysis and mean light intensity of Whitmire Nova trap 2 at

Position a2

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition a2

Trap 2 Mean light intensity 1.34 ± 0.09 lumens/m2

84

Figure C-3. Spectral analysis and mean light intensity of Whitmire Nova trap 3 at

Position b1

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition b1

Trap 3 Mean light intensity 1.35 ± 0.14 lumens/m2

85

Figure C-4. Spectral analysis and mean light intensity of Whitmire Nova trap 4 at

Position b2

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition b2

Trap 4 Mean light intensity 1.33 ± 0.17 lumens/m2

86

Figure C-5. Spectral analysis and mean intensity of overhead cool-white fluorescent light

at Position a1

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition a1

55.92 lumens/m2

87

Figure C-6. Spectral analysis and mean intensity overhead cool-white fluorescent light at

Position a2

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition a2

53.67 lumens/m2

88

Figure C-7. Spectral analysis and mean intensity overhead cool-white fluorescent light at

Position b1

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition b1

54.88 lumens/m2

89

Figure C-8. Spectral analysis and mean intensity overhead cool-white fluorescent light at

Position b2

0

1000

2000

3000

4000

200 300 400 500 600 700 800

Intensity (counts)

Wavelength (nm)

MasterPosition b2

55.01 lumens/m2

90

APPENDIX D REARING CONDITIONS FOR CONLONIES OF MUSCA DOMESTICA

20

21

22

23

24

25

26

27

28

29

30

08/0

3/05

09:

59:0

1.0

08/0

3/05

12:

03:3

1.0

08/0

3/05

14:

08:0

1.0

08/0

3/05

16:

12:3

1.0

08/0

3/05

18:

17:0

1.0

08/0

3/05

20:

21:3

1.0

08/0

3/05

22:

26:0

1.0

08/0

4/05

00:

30:3

1.0

08/0

4/05

02:

35:0

1.0

08/0

4/05

04:

39:3

1.0

08/0

4/05

06:

44:0

1.0

08/0

4/05

08:

48:3

1.0

08/0

4/05

10:

53:0

1.0

08/0

4/05

12:

57:3

1.0

08/0

4/05

15:

02:0

1.0

08/0

4/05

17:

06:3

1.0

08/0

4/05

19:

11:0

1.0

08/0

4/05

21:

15:3

1.0

08/0

4/05

23:

20:0

1.0

08/0

5/05

01:

24:3

1.0

08/0

5/05

03:

29:0

1.0

08/0

5/05

05:

33:3

1.0

08/0

5/05

07:

38:0

1.0

08/0

5/05

09:

42:3

1.0

Deg

rees

(C)

Figure D-1. Temperature (C°) of rearing room for adult Musca domestica recorded by

HOBO Temp & RH data logger

Mean Temperature 26.41 ± 0.19 C°

91

50

52

54

56

58

60

62

64

66

68

08/0

3/05

09:

59:0

1.0

08/0

3/05

12:

02:0

1.0

08/0

3/05

14:

05:0

1.0

08/0

3/05

16:

08:0

1.0

08/0

3/05

18:

11:0

1.0

08/0

3/05

20:

14:0

1.0

08/0

3/05

22:

17:0

1.0

08/0

4/05

00:

20:0

1.0

08/0

4/05

02:

23:0

1.0

08/0

4/05

04:

26:0

1.0

08/0

4/05

06:

29:0

1.0

08/0

4/05

08:

32:0

1.0

08/0

4/05

10:

35:0

1.0

08/0

4/05

12:

38:0

1.0

08/0

4/05

14:

41:0

1.0

08/0

4/05

16:

44:0

1.0

08/0

4/05

18:

47:0

1.0

08/0

4/05

20:

50:0

1.0

08/0

4/05

22:

53:0

1.0

08/0

5/05

00:

56:0

1.0

08/0

5/05

02:

59:0

1.0

08/0

5/05

05:

02:0

1.0

08/0

5/05

07:

05:0

1.0

08/0

5/05

09:

08:0

1.0

Rel

ativ

e H

umid

ity (%

)

Figure D-2. Relative Humidity (%) of rearing room for adult Musca domestica recorded

by HOBO Temp & RH data logger

Mean RH 59.94 ± 0.78%

92

0

2

4

6

8

10

12

14

16

18

08/0

3/05

10:

01:1

8.0

08/0

3/05

11:

56:4

8.0

08/0

3/05

13:

52:1

8.0

08/0

3/05

15:

47:4

8.0

08/0

3/05

17:

43:1

8.0

08/0

3/05

19:

38:4

8.0

08/0

3/05

21:

34:1

8.0

08/0

3/05

23:

29:4

8.0

08/0

4/05

01:

25:1

8.0

08/0

4/05

03:

20:4

8.0

08/0

4/05

05:

16:1

8.0

08/0

4/05

07:

11:4

8.0

08/0

4/05

09:

07:1

8.0

08/0

4/05

11:

02:4

8.0

08/0

4/05

12:

58:1

8.0

08/0

4/05

14:

53:4

8.0

08/0

4/05

16:

49:1

8.0

08/0

4/05

18:

44:4

8.0

08/0

4/05

20:

40:1

8.0

08/0

4/05

22:

35:4

8.0

08/0

5/05

00:

31:1

8.0

08/0

5/05

02:

26:4

8.0

08/0

5/05

04:

22:1

8.0

08/0

5/05

06:

17:4

8.0

Lum

ens

Figure D-3. Light intensity (lumens/m2) of rearing room for adult Musca domestica

recorded by HOBO Light Intensity data logger. Graph illustrates 12:12 (L:D) photoperiod

Mean Intensity 10.28 ± 2.38 lumens/m2

93

20

21

22

23

24

25

26

27

28

29

30

03/0

4/05

15:

58:3

4.0

03/0

4/05

23:

06:0

4.0

03/0

5/05

06:

13:3

4.0

03/0

5/05

13:

21:0

4.0

03/0

5/05

20:

28:3

4.0

03/0

6/05

03:

36:0

4.0

03/0

6/05

10:

43:3

4.0

03/0

6/05

17:

51:0

4.0

03/0

7/05

00:

58:3

4.0

03/0

7/05

08:

06:0

4.0

03/0

7/05

15:

13:3

4.0

03/0

7/05

22:

21:0

4.0

03/0

8/05

05:

28:3

4.0

03/0

8/05

12:

36:0

4.0

03/0

8/05

19:

43:3

4.0

03/0

9/05

02:

51:0

4.0

03/0

9/05

09:

58:3

4.0

03/0

9/05

17:

06:0

4.0

03/1

0/05

00:

13:3

4.0

03/1

0/05

07:

21:0

4.0

03/1

0/05

14:

28:3

4.0

03/1

0/05

21:

36:0

4.0

03/1

1/05

04:

43:3

4.0

03/1

1/05

11:

51:0

4.0

Tem

pera

ture

(C)

Figure D-4. Temperature (C°) of rearing room for Musca domestica larvae recorded by

HOBO Temp & RH data logger

Mean Temperature 26.19 ± 0.42 C°

94

0

10

20

30

40

50

60

70

03/0

4/05

15:

58:3

4.0

03/0

4/05

23:

03:3

4.0

03/0

5/05

06:

08:3

4.0

03/0

5/05

13:

13:3

4.0

03/0

5/05

20:

18:3

4.0

03/0

6/05

03:

23:3

4.0

03/0

6/05

10:

28:3

4.0

03/0

6/05

17:

33:3

4.0

03/0

7/05

00:

38:3

4.0

03/0

7/05

07:

43:3

4.0

03/0

7/05

14:

48:3

4.0

03/0

7/05

21:

53:3

4.0

03/0

8/05

04:

58:3

4.0

03/0

8/05

12:

03:3

4.0

03/0

8/05

19:

08:3

4.0

03/0

9/05

02:

13:3

4.0

03/0

9/05

09:

18:3

4.0

03/0

9/05

16:

23:3

4.0

03/0

9/05

23:

28:3

4.0

03/1

0/05

06:

33:3

4.0

03/1

0/05

13:

38:3

4.0

03/1

0/05

20:

43:3

4.0

03/1

1/05

03:

48:3

4.0

03/1

1/05

10:

53:3

4.0

Rel

ativ

e H

umid

ity (%

)

Figure D-5. Relative Humidity (%) of rearing room for Musca domestica larvae recorded

by HOBO Temp & RH data logger

Mean RH 51.03 ± 3.49%

95

0

2

4

6

8

10

12

08/0

3/05

10:

03:3

0.0

08/0

3/05

12:

05:0

0.0

08/0

3/05

14:

06:3

0.0

08/0

3/05

16:

08:0

0.0

08/0

3/05

18:

09:3

0.0

08/0

3/05

20:

11:0

0.0

08/0

3/05

22:

12:3

0.0

08/0

4/05

00:

14:0

0.0

08/0

4/05

02:

15:3

0.0

08/0

4/05

04:

17:0

0.0

08/0

4/05

06:

18:3

0.0

08/0

4/05

08:

20:0

0.0

08/0

4/05

10:

21:3

0.0

08/0

4/05

12:

23:0

0.0

08/0

4/05

14:

24:3

0.0

08/0

4/05

16:

26:0

0.0

08/0

4/05

18:

27:3

0.0

08/0

4/05

20:

29:0

0.0

08/0

4/05

22:

30:3

0.0

08/0

5/05

00:

32:0

0.0

08/0

5/05

02:

33:3

0.0

08/0

5/05

04:

35:0

0.0

08/0

5/05

06:

36:3

0.0

Lum

ens

Figure D-6. Light intensity (lumens/m2) of rearing room for Musca domestica larvae

recorded by HOBO Light Intensity data logger. Graph illustrates 12:12 (L:D) photoperiod

Mean Intensity 6.67 ± 1.44 lumens/m2

96

LIST OF REFERENCES

Agee, H. R., V. M. Kirk, and J. C. Davis. 1983. Comparative spectral sensitivity and some observations on vision related behavior of northern and western corn rootworm adults (Diabrotica: Coleoptera). J. Ga. Entomol. Sci. 18: 240-245.

Agee, H. R. and R. S. Patterson. 1983. Spectral sensitivity of stable, face, and horn flies

and behavioral responses of stable flies to visual traps (Diptera: Muscidae). Environ. Entomol. 12: 1823-1828.

Axtell, R. C. 1970. Integrated fly control program for caged-poultry houses. J. Econ.

Entomol. 63: 400-405. Barnard, D. R. and C. J. Geden. 1993. Influence of larval density and temperature in

poultry manure on development of the house fly (Diptera: Muscidae). Environ. Entomol. 22: 971-977.

Barnard, D. R., R. H. Harms, and D. R. Sloan. 1998. Biodegradation of poultry

manure by house fly (Diptera: Muscidae). Environ. Entomol. 27: 600-605. Bellingham, J. 1995. A comparative study of the spectral sensitivity, antennal sensilla,

and landing preferences of the house fly, Musca domestica (L.) (Diptera: Muscidae), and the lesser house fly, Fannia canicularis (L.) (Diptera: Fanniidae), Dissertation, Biology. Queens University, Belfast. pp. 130.

Bidawid, S. P., J. F. B. Edeson, J. Ibrahim, and R. M. Matossian. 1978. The role of

non-biting flies in the transmission of enteric pathogens (Salmonella species and Shigella species) in Beirut, Lebanon. Ann. Trop. Med. Parasitol. 72: 117-121.

Borror, D. J., C. A. Triplehorn, and N. F. Johnson. 1989. An introduction to the study

of insects. Harcourt Brace College Pubishers, Fort Worth, TX. Bowden, J. 1973. The influence of moonlight on catches of insects in light traps in

Africa. Part I. The moon and moonlight. Bull. Ent. Res. 63: 113-128. Bowden, J. 1982. An analysis of factors affecting catches of insects in light traps. Bull.

Ent. Res. 72: 535-556. Bowden, J. and B. M. Church. 1973. The influence of moonlight on catches of insects

in light traps in Africa. Part II. The effect of moon phase on light trap catches. Bull. Ent. Res. 63: 129-142.

97

Bryant, E. H. 1970. The effect of egg density on hatchability in two strains of the housefly. Physiol. Zool. 43: 288-295.

Buchan, P. B. and R. S. Sohal. 1981. Effect of temparature and different sex ratios on

physical activity and life span in the adult housefly, Musca domestica. Exp. Geront. 16: 223-228.

Buchan, P. B. and R. B. Moreton. 1981. Flying and walking of small insects (Musca

domestica) recorded differentially with a standing-wave radar actograph. Physiol. Entomol. 6: 149-155.

Burg, J. G. and R. C. Axtell. 1984. Monitoring house fly, Musca domestica (Diptera:

Muscidae), populations in cage-layer poultry houses using a baited jug-trap. Environ. Entomol. 13: 1083-1090.

Carlson, D. A. and M. Beroza. 1973. Field evaluations of (Z)-9-tricosene, a sex

attractant pheromone of the house fly. Environ. Entomol. 2: 555-559. Carlson, D. A., R. E. Doolittle, M. Beroza, W. M. Ragoff, and G. H. Gretz. 1974.

Muscalure and related compounds. I. Response of houseflies in olfactometer and pseudofly tests. J. Agr. Food Chem. 22: 194-196.

Chapman, J. W., P. E. Howse, J. J. Knapp, and D. Goulson. 1998. Evaluation of three

(Z)-9-tricosene formulations for control of Musca domestica (Diptera: Muscidae) in caged-layer poultry units. J. Econ. Entomol. 91: 915-922.

Chapman, J. W., J. J. Knapp, and D. Goulson. 1999. Visual responses of Musca

domestica to pheromone impregnated targets in poultry units. Med. Vet. Entomol. 13: 132-138.

Cosse, A. A. and T. C. Baker. 1996. House flies and pig manure volatiles: Wind tunnel

behavioral studies and electrophysiological evaluations. J. Agric. Entomol. 13: 301-317.

Deimel, E. and K. Kral. 1992. Long term sensitivity adjustment of the compound eyes

of the housefly, Musca domestica, during early adult life. J. Insect Physiol. 38: 425-430.

Driggers, D. P. 1971. Field evaluation of blacklight electrocutor grids for the control of

flies associated with poultry, Masters Thesis, Entomology and Nematology. University of Florida, Gainesville, pp. 33.

Elvin, M. K. and E. S. Krafsur. 1984. Relationship between temperature and rate of

ovarian development in the house fly, Musca domestica L. (Diptera: Muscidae). Ann. Entomol. Soc. Amer. 77: 50-55.

98

Fatchurochim, S., C. J. Geden, and R. C. Axtell. 1989. Filth fly (Diptera) oviposition and larval devlopment in poultry manure of various moisture levels. J. Entomol. Sci. 24: 224-231.

Fletcher, M. G., R. C. Axtell, and R. E. Stinner. 1990. Longevity and fecundity of

Musca domestica (Diptera: Muscidae) as a function of temperature. J. Med. Entomol. 27: 922-926.

Fukushi, T. 1976. Classical conditioning to visual stumuli in the housefly, Musca

domestica. J. Ins. Physiol. 22: 361-364. Geden, C. J., J. A. Hogsette, and R. D. Jacobs. 1999. Effect of airflow on house fly

(Diptera: Muscidae) distribution in poultry houses. J. Econ. Entomol. 92: 416-420.

Goldsmith, T. H. and H. R. Fernandez. 1968. The sensitivity of housefly

photoreceptors in the mid-ultraviolet and the limits of the visible spectrum. J. Exp. Biol. 49: 669-677.

Graczyk, T. K., R. K. Knight, R. H. Gilman, and M. R. Cranfield. 2001. The role of

non-biting flies in the epidemiology of human infectious diseases. Microbes and Infection 3: 231-235.

Green, C. H. 1984. A comparison of phototactic responses to red and green light in

Glossina morsitans and Musca domestica. Physiol. Entomol. 16: 165-172. Greenberg, B. 1973. Flies and disease, Volume 2. Biology and disease transmission.

Princeton University Press, Princeton, NJ. Gruebel, P., J. S. Hoffman, F. K. Chong, N. A. Burstein, C. Mepani, and D. R. Cave.

1997. Vector potential of houseflies (Musca domestica) for Helicobactero pylori. J. Clin. Microbiol. 35: 1300-1303.

Haupt, A. and J. R. Busvine. 1968. The effect of overcrowding on the size of houseflies

(Musca domestica L.). Trans. R. Ent. Soc. Lond. 120: 297-311. Hecht, O. 1970. Light and color reactions of Musca domestica under different

conditions. Bull. Ent. Res. 16: 94-98. Hogsette, J. A. 1992. New diets for production of house flies and stable flies (Diptera:

Muscidae) in the laboratory. J. Econ. Entomol. 85: 2291-2294. Hogsette, J. A. 1995. The house fly: Basic biology and ecology, pp. 71-76. In H. H. Van.

Horn [ed.], Nuisance concerns in animal manure management: Odors and flies. Florida Cooperative Extension, University of Florida, Gainesville, FL.

99

Hogsette, J. A. 1996. Development of house flies (Diptera: Muscidae) in sand containing varying amounts of manure solids and moisture. J. Econ. Entomol. 89: 940-945.

Hogsette, J. A. 2003. United States Department of Agriculture - Agricultural Research

Service research on veterinary pests. Pest Manag. Sci. 59: 835-841. Hogsette, J. A., D. A. Carlson, and A. S. Nejame. 2002. Development of granular boric

acid sugar baits for house flies (Diptera: Muscidae). J. Econ. Entomol. 95: 1110-1112.

Hogsette, J. A. and R. Farkas. 2000. Secretophagus and haematophagus higher Diptera.

Manual of Palearctic Diptera, General and Applied Dipterology. 1: 769-792. Hogsette, J. A., R. D. Jacobs, and R. W. Miller. 1993. The sticky card: Device for

studying the distribution of adult house fly (Diptera: Muscidae) populations in closed poultry houses. J. Econ. Entomol. 86: 450-454.

Hribar, L. J., D. J. Leprince, and L. D. Foil. 1991. Increasing horse fly (Diptera:

Tabanidae) catch in canopy traps by reducing ultraviolet light reflectance. J. Med. Entomol. 28: 874-877.

Hulley, P. E. 1986. Factors affecting numbers of Musca domestica Linnaeus (Diptera:

Muscidae) and some other flies breeding in poultry manure. J. Entomol. Soc. S. Afr. 49: 19-27.

Imai, C. 1984. Population dynamics of houseflies, Musca domestica, on experimentally

accumulated refuse. Res. Popul. Ecol. 26: 353-362. Iwasa, M., S. I. Makino, H. Asakura, H. Kobori, and Y. Morimoto. 1999. Detection

of Escherichia coli 0157:H7 from Musca domestica (Diptera: Muscidae) at a cattle farm in Japan. J. Med. Entomol. 36: 108-112.

Keiding, J. 1965. Observations on the behavior of the housefly in relation to its control.

Revisita di Parassitologia 26: 45-60. Krafsur, E. S. 1985. Age composition and seasonal phenology of house fly (Diptera:

Muscidae) populations. J. Med. Entomol. 22: 515-523. Lemke, L. A., P. G. Koehler, and R. S. Patterson. 1990. Laboratory method for

measuring the attractiveness of pheromones to adult Musca domestica (Diptera: Muscidae). J. Med. Entomol. 27: 1062-1064.

Levine, O. S. and M. M. Levine. 1991. Houseflies (Musca domestica) as mechanical

vectors of Shigellosis. Res. Infect. Dis. 13: 688-696.

100

Lillie, T. H. and J. Goddard. 1987. Operational testing of electrocutor traps for fly control in dining facilities. J. Econ. Entomol. 80: 826-829.

Luvchiev, V. I., M. P. Zhelyazova, and I. A. Krusteva. 1985. Actographic studies on

the locomotive activity of the house fly (Musca domestica L.). Ecology 15: 50-59. Lysyk, T. J. 1991a. Effects of temperature, food, and sucrose feeding on longevity of the

house fly (Diptera: Muscidae). Environ. Entomol. 20: 1176-1180. Lysyk, T. J. 1991b. Modeling oviposition of the house fly (Diptera: Muscidae). Can.

Entomol. 123: 345-352. Lysyk, T. J. and R. C. Axtell. 1986. Movement and distibution of house flies (Diptera:

Muscidae) between habitats in two livestock farms. J. Econ. Entomol. 79: 993-998.

McAlpine, J. F. [ed.] 1987. Manual of Nearctic Diptera. Biosystematics Research

Centre, Ottowa, Ontario. McCann, G. D. and D. W. Arnett. 1972. Spectral and polarization sensitivity of the

Dipteran visual system. J. Gen. Physiol. 59: 534-558. Meyer, J. A., C. M. Christensen, and F. W. Knapp. 1978. The influence of time of

day, bovine manure type, and distance from a barn on the recovery of face fly and house fly pupae. Environ. Entomol. 7: 246-48.

Mian, L. S., H. Maag, and J. V. Tacal. 2002. Isolation of Salmonella from muscoid

flies at commercial animal establishments in San Bernardino County, California. J. Vector Ecol. 27: 82-85.

Mitchell, E. R., F. C. Tingle, and D. A. Carlson. 1975. Effect of muscalure on house

fly traps of different color and location in poultry houses. J. Ga. Entomol. Soc. 10: 168-174.

Monzon, R. B., A. R. Sanchez, B. M. Tadiaman, O. A. Najos, E. G. Valencia, R. R.

Rueda, and J. V. M. Ventura. 1991. A comparison of the role of Musca domestica (Linnaeus) and Chrysoma megacephala (Fabricius) as mechanical vectors of helminthic parasites in a typical slum area of metropolitan Manila. Southeast Asian J. Trop. Med. Public Health 22: 222-228.

Moon, R. D. 2002. Muscid flies (Muscidae), pp. 597. In G. R. Mullen and L. Durden

[eds.], Medical and Veterinary Entomology. Academic Press, Boston. Morgan, P. B., I. H. Gilbert, and R. E. Fye. 1974. Evaluation of (Z)-9-tricosene for

attractancy for Musca domestica in the field. Fla. Ent. 57: 136-140.

101

Morris, A. P. and E. J. Hansen. 1966. Dispersion of insecticide-resistant populations of the house fly, Musca domestica L. J. Econ. Entomol. 59: 45-50.

Mulla, M. S., H. Axelrod, and Y. Hwang. 1979. Potentiation between physical and

chemical attractants against house flies. Bull. Soc. Vector Ecol. 4: 36-39. Mulla, M. S., Y. Hwang, and H. Axelrod. 1977. Attractants for synanthropic flies:

Chemical attractants for domestic flies. J. Econ. Entomol. 70: 644-648. Philipsborn, V. A. and T. Labhart. 1990. A behavioral study of polarization vision in

the fly, Musca domestica. J. Comp. Physiol. A 167: 737-743. Pickens, L. G. 1989a. Factors affecting the distance of scatter of house flies (Diptera:

Muscidae) from electrocuting traps. J. Econ. Entomol. 82: 149-151. Pickens, L. G. 1989b. Relative attractiveness of paired BL and BLB fluorescent bulbs

for house and stable flies (Diptera: Muscidae). J. Econ. Entomol. 82: 535-538. Pickens, L. G. 1990. Colorimetric versus behavioral studies of face fly (Diptera:

Muscidae) vision. Environ. Entomol. 19: 1242-1252. Pickens, L. G. 1995. Baited fly traps - 1900 to 1995. IPM Practitioner 17: 1-6. Pickens, L. G., J. Jaworski, and M. J. G. D. 1994. Traps and baits for flies (Diptera) on

Pacific islands. J. Med. Entomol. 31: 828-832. Pickens, L. G. and R. W. Miller. 1987. Techniques for trapping flies on dairy farms. J.

Agric. Entomol. 4: 305-313. Pickens, L. G., R. W. Miller, and L. E. Campbell. 1975. Bait-light combinations

evaluated as attractants for house flies and stable flies (Diptera: Muscidae). J. Med. Entomol. 11: 749-751.

Pickens, L. G., R. W. Miller, and G. R. Mowry. 1973. An improved bait for flies

(Diptera: Muscidae, Calliphoridae). J. Med. Entomol. 10: 84-88. Pickens, L. G. and G. D. Mills, Jr. 1993. Solar-powered electrocuting trap for

controlling house flies and stable flies (Diptera: Muscidae). J. Med. Entomol. 30: 872-877.

Pickens, L. G., N. O. Morgan, J. G. Hartsock, and J. W. Smith. 1967. Dispersal

patterns and populations of the house fly affected by sanitation and weather in rural Maryland. J. Econ. Entomol. 60: 1250-1255.

102

Pickens, L. G., N. O. Morgan, and R. W. Thimijan. 1969. House fly response to fluorescent lamps: Influenced by fly age and nutrition, air temperature, and position of lights. J. Econ. Entomol. 62: 536-539.

Pickens, L. G. and R. W. Thimijan. 1986. Design parameters that affect the

performance of UV-emitting traps in attracting house flies (Diptera: Muscidae). J. Econ. Entomol. 79: 1003-1009.

Rady, M. H., N. A. Raouf, I. Labib, and A. I. Merdan. 1992. Bacterial contamination

of the housefly Musca domestica collected from 4 hospitals at Cairo. J. Egypt Soc. Parasitol. 22: 279-288.

Ragland, S. S. and R. S. Sohal. 1973. Mating behavior, physical activity and aging in

the housefly, Musca domestica. Exp. Geront. 8: 135-145. Roberts, A. E., P. R. Syms, and L. J. Goodman. 1992. Intensity and spectral emission

as factors affecting the efficacy of an insect electrocutor trap towards the house fly. Entomol. Exp. Appl. 64: 259-268.

Rockstein, M., J. A. Chesky, M. H. Levy, and L. Yore. 1981. Effect of population

density upon life expectancy and wing retention in the common house fly, Musca domestica L. Gerontology 27: 13-19.

Rubio-Palis, Y. 1992. Influence of moonlight on light trap catches of the malaria vector

Anopheles nuneztovari in Venezuela. J. Am. Mosq. Control Assoc. 8: 178-183. Rutz, D. A., G. A. Scoles, and G. G. Howser. 1988. Evaluation of fly-electrocuting

black light devices in caged-layer poultry facilities. Poultry Sci. 67: 871-877. Sacca, G. 1964. Comparative bionomics in the genus Musca. Ann. Rev. Entomol. 9: 341-

358. SAS Institute. 2001. SAS Stat User's Guide Version 8.01. SAS Institute, Cary, NC. Sasaki, T., M. Kobayashi, and N. Agui. 2000. Epidemiological potential of excretion

and regurgitation by Musca domestica (Diptera: Muscidae) in the dissemination of Escherichia coli 0157:H7 to food. J. Med. Entomol. 37: 945-949.

Schoof, H. F. and R. E. Silverly. 1954a. Privies as a source of fly population in an urban

area. Am. J. Trop. Med. Hyg. 3: 930-935. Schoof, H. F. and R. E. Silverly. 1954b. Urban fly dispersion studies with special

reference to movement pattern of Musca domestica. Am. J. Trop. Med. Hyg. 3: 539-547.

103

Semakula, L. M., R. A. J. Taylor, and C. W. Pitts. 1989. Flight behavior of Musca domestica and Stomoxys calcitrans (Diptera: Muscidae) in a Kansas dairy barn. J. Med. Entomol. 26: 501-509.

Shields, E. J. 1989. Artificial light: Experimental problems with insects. Bull. Entomol.

Soc. Amer. 35: 40-44. Singh, N., A. K. Mishra, C. F. Curtis, and V. P. Sharma. 1996. Influence of moonlight

on light-trap catches of the malaria vector Anopheles culicifacies (Diptera: Culicidae) in central India. Bull. Ent. Res. 86: 475-479.

Skovmand, O. and H. Mourier. 1986. Electrocuting light traps evaluated for the control

of house flies. J. Appl. Ent. 102: 446-455. Snell, E. 1998. Factors affecting laboratory procedures for evaluating efficacy of insect

light traps for house flies, pp. 187-198, International Conference on Urban Pests, Charleston, SC.

Stafford III, K. C., C. H. Collison, and J. G. Burg. 1988. House fly (Diptera:

Muscidae) monitoring method comparisons and seasonal trends in environmentally controlled high-rise, caged-layer poultry houses. J. Econ. Entomol. 81: 1426-1430.

Sucharit, S. and W. Tumrasvin. 1981. The diurnal activities of Musca domestica

Linnaeus and Chrysomyia megacephala Fabricius in Bangkok. Jap. J. Sanit. Zool. 32: 334-336.

Sulaiman, S., M. Z. Othman, and A. H. Aziz. 2000. Isolations of enteric pathogens

from synanthropic flies trapped in downtown Kuala Lumpur. J. Vector Ecol. 25: 90-93.

Syms, P. R. and L. J. Goodman. 1987. The effect of flickering U-V light output on the

attractiveness of an insect electrocutor trap to the house fly, Musca domestica. Entomol. Exp. Appl. 43: 81-85.

Tan, S. W., K. L. Yap, and H. L. Lee. 1997. Mechanical transport of rotavirus by the

legs and wings of Musca domestica (Diptera: Muscidae). J. Med. Entomol. 34: 527-531.

Thimijan, R. W. and L. G. Pickens. 1973. A method for predicting house fly attraction

of electromagnetic radiant energy. J. Econ. Entomol. 66: 95-100. Tsutsumi, C. 1968. Studies on the behavior of the housefly, Musca domestica L. II.

Some environmental factors affecting the nighttime resting behavior of flies. Japan. J. Med. Sci. Biol. 21: 195-204.

104

West, L. S. 1951. The Housefly. Comstock Publishing Company Inc., Ithaca, NY. Zurek, L., S. S. Denning, C. Schal, and D. W. Watson. 2001. Vector competence of

Musca domestica (Diptera: Muscidae) for Yersinia pseudotuberculosis. J. Med. Entomol. 38: 333-335.

105

BIOGRAPHICAL SKETCH

Matthew D. Aubuchon, son of David and Claire Aubuchon, was born February 7,

1974, in St. Louis, Missouri. He graduated from St. Louis University High School in

1992. After high school, he attended Indiana University and graduated with honors in

1996 after completing the requirements for the degree of Bachelor of Science with a

major in environmental science and public policy. During his senior year of college,

Matt moved to Washington, D.C., for an internship at the nonprofit organization Center

for Policy Alternatives. During the summers of 1995 through 1997, Matt acquired his

aquatic-applicator license and worked on over 100 lakes throughout Indiana and

Michigan abating invasive species of aquatic plants. Matt moved to Auburn in Fall of

1997 and worked as a laboratory technician for the Auburn University Department of

Entomology. In winter, 1998, he was accepted into the graduate entomology program at

Auburn University, where he pursued his master’s degree under the guidance of Dr. Gary

Mullen. After finishing his M.S. in August, 2001, Matt promptly moved to Gainesville,

FL, to pursue his Ph.D. at the Entomology and Nematology Department under the

guidance of Dr. Phil Koehler. On April 23, 2005, Matt was married to Amanda Kathleen

Chambliss in St. Augustine, FL.