Florida GALS Eradication ProgramMethods Development

Objectives• Chemical Control Techniques

– Molluscicide bait efficacy testing– Effective soil drench development

• Trap Development– Most effective trap design– Most effective attractants

• Nematode Detection– Is Angiostrongylus cantonensis widespread in Florida?

• Biological Studies– Time to reproductive maturity (defined by first egg laying event)– Growth rate over time and “natural” survivability– Clutch size and frequency of egg laying and effect of burial depth on egg hatch– Effect of population density on the animals– Source of chirality in A. fulica using traditional crosses and molecular techniques.

Molluscicide Evaluation• Kemp, N. J. and P.F. Newell. 1985. Laboratory observations on the

effectiveness of methiocarb and metaldehyde baits against the slug Deroceras reticulatum (Müll). J. Molluscan Studies 51: 228-229.

• Smith, T. R., J. White-McLean, K. Dickens, A. Howe and A. Fox. 2013. Efficacy of four molluscicides against the giant African snail, Lissachatina fulica Bowdich, (Gastropoda: Pulmonata). Florida Entomologist 96: 396-402.

• Ciomperlik, M.A., D.G. Robinson, I.H. Gibbs, A. Fields, T. Stevens and B.M. Taylor. 2013. Mortality to the giant African snail, Lissachatina fulica (Gastropoda: Achatinidae), and non-target snails using select molluscicides. Florida Entomologist 96: 370-379.

Metaldehyde Products With Residential Use Labels

• Molluscicides incorporated into the program– Bug-Geta – 3.25%

pellet metaldehyde – Hi-Yield Snail and Slug

Killer – 3.25% pellet metaldehyde

– Other 3.25% products available

Experimental Use Permit (EUP) Exemption Work

• Molluscicides Tested– SlugFest – 25% liquid

metaldehyde– Slugger – 4% mini-

pellet metaldehyde– Durham – 7.5%

granule metaldehyde

EUP exemption Results

Special Local Needs Label Update

• EUP exemption results accepted by AES and EPA

• SLN label requests – SlugFest (OrCal), Slugger (OrCal) and Deadline (AMVAC)

• Durham granules delayed – AMVAC unable to add bittering agent to a sand-based product (required by EPA)

• OrCal is working to develop a finer granule with bittering agent by further milling the mini-pellets

Soil Drenches• Natural Oils and Extracts:

caraway, cedar, cinnamon, clove, coffee, garlic, onion, mustard, and rosemary

• Nerve and Muscle Disruptors:thevetin and peruvoside (lucky nut plant), caffeine, digitoxin, oleandrin, cardiac glycosides and oxalates (too toxic?)

• Commercial Molluscicides: Pure’N’Natural Snail and Slug Away, Georgia Organic Solutions Neem 7-way, Global Aqua Solutions EF-211

• Traditional Drenches for Other Pests:imidacloprid, clothianidin, pyrethrins, fipronil, etofenprox, chlorothalonil, spinosad

New Trap Designs

• Inexpensive• Serviceable• Toxicant-free• Vertical or Horizontal• Prevent Escape

Rat Lungworm Testing

• Currently testing for:– Angiostrongylus

cantonensis• Could possibly

include the following species in the future: – A. costaricensis– A. dujardini– A. malaysiensis– A. vasorum

http://dpd.cdc.gov/dpdx/html/ImageLibrary/A-F/Angiostrongyliasis/body_Angiostrongyliasis_il5.htm

• Quantitative PCR• Traditional

identification using light microscopy

Rat Lungworm Testing Results

• Over 600 snails tested to date

• ~30 specimens can be tested per week

• Samples tested from 17 of the 21 Cores

• RLW detected in 7 Cores: 1, 2, 4, 5, 7, 12 and 15.

Biology Studies

• Egg Burial depth study

• Growth rate over time

• Reproductive Studies

• Self-fertilization rate

• Chirality Breeding Study

(dominant / recessive)

Egg Incubation Depth

• Eggs buried at a range of depths up to 17”• 15” seems to be near the limit

Growth Rates

20 40 60 80 100 120 140 160 180 20010.0

30.0

50.0

70.0

90.0

110.0

130.0Mean Snail Height

Days after hatch

Hei

ght (

mm

)

Single Lettuce

Single Synthetic DietPaired Lettuce

Paired Synthetic Diet

Single Lettuce

Single Synthetic Diet

Paired Lettuce

Paired Synthetic Diet

Days after Hatch

Height (mm) Width (mm) Whorls Weight 0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0146

81.1

44.1

6.76

56.02

139.2

91.3

49.9

7.01

90.26

Synthetic Diet

Lettuce

Average Time to First Egg Laying Average Parental Size

Reproductive Potential – Lab Studies

    Time of First Egg Laying Parental Size

    Months after Hatch Height (mm) All paired (2 snails

per cage) treatments Average: 4.8 86 (3.4 inches)

Minimum: 4.1 64 (2.5 inches)

N = 80

Reproductive Potential – Lab Studies• Average eggs/month = 730– Average egg viability = 51.3%– Average clutches/month = 2

• Greatest number of eggs produced by one cage– 5,146 eggs (10 clutches) in about 4 months. – 1 clutch tested for viability = 80%

• Largest Clutches: – 1082 eggs – 732 eggs (96.7% viable)

Self-Fertilization

Observations: Single, Lettuce =Non-viable Eggs

Paired, Lettuce = Viable Eggs

Viable Eggs!

~3 months

later

However:Single, Diet =

Key Biological Factors For the Program

• Self fertilization = Yes (average egg viability)• Sexual maturity = 4 months old (2.5 inches)• Adults can produce up to 625 eggs per month

(average 365 with 50% viability)• Eggs were observed hatching 26 days after egg

laying (average 5 – 7 days)• Neonate survival underground without food =

97 days• Possible period underground ≈ 120 days (4

months)

THANK YOU for your time and attention