Chemical Chemical Methods of Methods of

Vector ControlVector Control

Brian WellsBrian Wells

University of FloridaUniversity of Florida

December 3, 2003December 3, 2003

Why Control Why Control Mosquitoes?Mosquitoes?

Mosquitoes are the world's most significant Mosquitoes are the world's most significant vectors vectors

Diseases transmitted by mosquitoes are Diseases transmitted by mosquitoes are responsible for the deaths of millions of responsible for the deaths of millions of people every year. people every year.

Mosquitoes are the primary vector for Mosquitoes are the primary vector for several pathogens such as West Nile Virusseveral pathogens such as West Nile Virus

Story about FL: Story about FL: http://www.cnn.com/2001/HEALTH/07/07/flhttp://www.cnn.com/2001/HEALTH/07/07/florida.west.nile/orida.west.nile/

Medical Alert: Medical Alert: http://www.sawyerproducts.com/FLstate/O2http://www.sawyerproducts.com/FLstate/O2402FLWestNileVirusAlert.html402FLWestNileVirusAlert.html

Why Control Why Control Mosquitoes?Mosquitoes?

Mosquitoes also are the vector for St. Mosquitoes also are the vector for St. Louis Encephalitis, Eastern Equine Louis Encephalitis, Eastern Equine Encephalitis, and dengue fever.Encephalitis, and dengue fever.

WHO estimates thatWHO estimates that 50 million cases of dengue (24,000 deaths)50 million cases of dengue (24,000 deaths) 200,000 cases of yellow fever (30,000 200,000 cases of yellow fever (30,000

deaths)deaths) 300M to 500M cases of malaria (1M deaths)300M to 500M cases of malaria (1M deaths)

Why Control Why Control Mosquitoes?Mosquitoes?

The Most Important Reason:The Most Important Reason:

Mosquitoes can make Mosquitoes can make life very life very

uncomfortable!uncomfortable!

Mosquito Control in the Mosquito Control in the Gainesville areaGainesville area

Some quick facts on Gainesville:Some quick facts on Gainesville:45.52 square miles45.52 square milesPopulation of 117,182Population of 117,18287,509 households87,509 householdsMild winters, warm summersMild winters, warm summers

Source: http://www.cityofgainesville.org

City of Gainesville Mosquito City of Gainesville Mosquito Spray ZonesSpray Zones

Chemicals – Attacking Chemicals – Attacking Mosquitoes at Every LevelMosquitoes at Every Level

Chemical ControlsChemical Controls

Commonly used pesticidesCommonly used pesticides MalathionMalathion NaledNaled PermethrinPermethrin ResmethrinResmethrin SumithrinSumithrin

Chemical ControlsChemical Controls

MalathionMalathion One of the most commonly used pesticidesOne of the most commonly used pesticides Malathion is an adulticideMalathion is an adulticide Patented in 1951 by American Cyanamid Patented in 1951 by American Cyanamid

CompanyCompany Also a contact insecticide – that is, it can Also a contact insecticide – that is, it can

kill pests if it touches them or if they eat a kill pests if it touches them or if they eat a sprayed part of a plant sprayed part of a plant

Considered to be one of the safest Considered to be one of the safest organophosphate insecticidesorganophosphate insecticides

Chemical ControlsChemical Controls

MalathionMalathion Cholinesterase InhibitorCholinesterase Inhibitor Blocks neural transmissionBlocks neural transmission Effects on human can potentially be Effects on human can potentially be

muscle weakness, tremors, and even muscle weakness, tremors, and even death.death.

Although it is a generally safe pesticide, Although it is a generally safe pesticide, the real key to its safety is to use the real key to its safety is to use common sense and avoid unnecessary common sense and avoid unnecessary exposure.exposure.Source: http://www.napa.ufl.edu/oldnews/spray.htm

Chemical ControlsChemical Controls

Benefits of MalathionBenefits of Malathion Helps control the mosquito population Helps control the mosquito population

and thus improves QOLand thus improves QOL Protects crops in Florida that yield $10 Protects crops in Florida that yield $10

Billion worth of revenueBillion worth of revenue If these crops were lost, every man, If these crops were lost, every man,

woman, and child in Florida would have woman, and child in Florida would have to contribute an additional $700 to to contribute an additional $700 to maintain the standard of livingmaintain the standard of living

Source: http://fmel.ifas.ufl.edu/fmbuzz/wtchallenge2.htm

Chemical ControlsChemical Controls

LarvicidesLarvicides Methoprene – growth inhibitorMethoprene – growth inhibitor TemephosTemephos Mineral Oil can be used to form a thin Mineral Oil can be used to form a thin

film of the surface of water to cause the film of the surface of water to cause the larvae and pupa to drown.larvae and pupa to drown.

How are Pesticides How are Pesticides deployed?deployed?

AirplaneAirplane Ground truck-mounted sprayersGround truck-mounted sprayers Portable sprayersPortable sprayers

Problems facing chemical-Problems facing chemical-based vector controlbased vector control

Relatively small pesticide marketRelatively small pesticide market Small market creates little economic incentive Small market creates little economic incentive

for chemical companies to spend large for chemical companies to spend large amounts of money to develop and label new amounts of money to develop and label new chemical products chemical products

When a new chemical does become available, When a new chemical does become available, it is usually because it has a side-effect of it is usually because it has a side-effect of being lethal to mosquitoes being lethal to mosquitoes

Food Quality Protection Act - will help to Food Quality Protection Act - will help to assure that valuable public health pesticides assure that valuable public health pesticides are not lost through a lack of registrant are not lost through a lack of registrant support or unwillingness to pay for the risk support or unwillingness to pay for the risk management studies because the mosquito management studies because the mosquito control market is too small control market is too small

Problems facing chemical-Problems facing chemical-based vector controlbased vector control

Growing problem of mosquito resistanceGrowing problem of mosquito resistance Insects have the innate ability to stay one step Insects have the innate ability to stay one step

ahead of us by developing resistance to the ahead of us by developing resistance to the relatively few products availablerelatively few products available

The AMCA advocates the practicing of The AMCA advocates the practicing of resistance management techniques that resistance management techniques that attempt to minimize the risk of mosquitoes attempt to minimize the risk of mosquitoes becoming resistant to the existing chemicalsbecoming resistant to the existing chemicals

Ex: not using sublethal amounts of Ex: not using sublethal amounts of insecticides, the rotating/alternating of insecticides, the rotating/alternating of available chemicals available chemicals

Source: http://www.epa.gov/oppbppd1/PESP/strategies/backgrounders/amca-bk.htm

What constitutes a What constitutes a successful Mosquito successful Mosquito

Control program?Control program? Source ReductionSource Reduction

SanitationSanitation Impoundment ManagementImpoundment Management Open Marsh Water ManagementOpen Marsh Water Management

LarvicidingLarviciding AdulticidingAdulticiding Biological Controls (more on Friday)Biological Controls (more on Friday) Mosquito-transmitted Disease Mosquito-transmitted Disease

SurveillanceSurveillance

Cost of Mosquito ControlCost of Mosquito Control

In FY 2002, Gainesville spent In FY 2002, Gainesville spent $285,389 ($2.44 per person)$285,389 ($2.44 per person)

In FY 2003, Gainesville will spend In FY 2003, Gainesville will spend $480,915 ($4.11 per person)$480,915 ($4.11 per person)

Individual chemical costsIndividual chemical costs Malathion – 5lbs - $6.15Malathion – 5lbs - $6.15 Pyrethrin – 1qt of concentrate - $97.95Pyrethrin – 1qt of concentrate - $97.95 Permethrin – 1 qt of concentrate - $37.95Permethrin – 1 qt of concentrate - $37.95 BTI - $24.95 for 20 briquetsBTI - $24.95 for 20 briquets

How is Gainesville How is Gainesville Mosquito Control Doing?Mosquito Control Doing?

Citizen Opinion Survey – 1999Citizen Opinion Survey – 1999 5% - Excellent5% - Excellent 43% - Good43% - Good 32% - Fair32% - Fair 20% - Poor20% - Poor 61% - Very Important61% - Very Important 32% - Somewhat Important32% - Somewhat Important 8% - Not Important8% - Not Important

Source: http://www.cityofgainesville.org/gov/issues/citsurv99.cfm

How is Gainesville How is Gainesville Mosquito Control Doing?Mosquito Control Doing?

Citizen Opinion Survey – 2000Citizen Opinion Survey – 2000 9% - Excellent9% - Excellent 44% - Good44% - Good 32% - Fair32% - Fair 16% - Poor16% - Poor 64% - Very Important64% - Very Important 30% - Somewhat Important30% - Somewhat Important 7% - Not Important7% - Not Important

Source: http://www.cityofgainesville.org/gov/issues/citsurv00.cfm

What can you do to help?What can you do to help?

Clean out eaves, troughs, and gutters. Clean out eaves, troughs, and gutters. Remove old tires or drill holes in those Remove old tires or drill holes in those

used in playgrounds to drain. used in playgrounds to drain. Turn over or remove empty plastic Turn over or remove empty plastic

pots. pots. Pick up all beverage containers and Pick up all beverage containers and

cups. cups. Check tarps on boats or other Check tarps on boats or other

equipment that may collect water. equipment that may collect water.

What can you do to help?What can you do to help?

Pump out bilges on boats. Pump out bilges on boats. Replace water in birdbaths and pet or Replace water in birdbaths and pet or

other animal feeding dishes at least other animal feeding dishes at least once a week. once a week.

Change water in plant trays, including Change water in plant trays, including hanging plants, at least once a week. hanging plants, at least once a week.

Remove vegetation or obstructions in Remove vegetation or obstructions in drainage ditches that prevent the flow drainage ditches that prevent the flow of water.of water.

How to Protect YourselfHow to Protect Yourself

5 D’s and 1 S5 D’s and 1 S Dusk and Dawn – avoid being outdoors Dusk and Dawn – avoid being outdoors

during this timeduring this time Dress – wear protective clothingDress – wear protective clothing DEET – mosquito repellantDEET – mosquito repellant Drainage – get rid of standing waterDrainage – get rid of standing water

ANDAND Screens – make sure windows are Screens – make sure windows are

closed and sealedclosed and sealedSource: http://www.health.ufl.edu/shcc/pdf/wnv.pdf

Questions?Questions?

Question 1Question 1

Malathion is a ________ pesticide that Malathion is a ________ pesticide that kills mosquitoes in the _______ stage kills mosquitoes in the _______ stage of life.of life.

A. organophosphate, larvaeA. organophosphate, larvae B. organophosphate, adultB. organophosphate, adult C. organohalide, larvaeC. organohalide, larvae D. organohalide, adultD. organohalide, adult

Question 2Question 2

Which of the following was not Which of the following was not mentioned as a commonly used mentioned as a commonly used pesticide?pesticide?

A. MalathionA. Malathion B. ResmethrinB. Resmethrin C. PermethrinC. Permethrin D. AtorvastatinD. Atorvastatin

Question 3Question 3

DEET is:DEET is: A. a personal insect repellantA. a personal insect repellant B. a sprayer used on trucksB. a sprayer used on trucks C. the acronym for the law C. the acronym for the law

governing mosquito controlgoverning mosquito control D. A brand of speakers at Best BuyD. A brand of speakers at Best Buy

Additional InformationAdditional Information

This presentation is available for This presentation is available for download at:download at:

http://www.destination-web.com/ees/http://www.destination-web.com/ees/vectors.pdfvectors.pdf