Integrated Pest Integrated Pest Management of Mosquitoes Management of Mosquitoes

to Control the Spread of to Control the Spread of West Nile Virus.West Nile Virus.

Melissa GreeneMelissa Greene

Keith MurphyKeith Murphy

Phyllis RobinsonPhyllis Robinson

What is an IPM? What is an IPM? • Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term

prevention of pests or their damage through a combination of techniques such as biological prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant control, habitat manipulation, modification of cultural practices, and use of resistant varieties.varieties.

• Pesticides are used only after monitoring indicates they are needed according to established Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism.guidelines, and treatments are made with the goal of removing only the target organism.

• Pest control materials are selected and applied in a manner that minimizes risks to human Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and non-target organisms, and the environment.health, beneficial and non-target organisms, and the environment.

A SEM of aA SEM of a mosquito.mosquito.

• West Nile virus was first isolated from an adult woman in the West West Nile virus was first isolated from an adult woman in the West Nile District of Uganda in 1937. The ecology was characterized in Nile District of Uganda in 1937. The ecology was characterized in Egypt in the 1950s. The virus became recognized as a cause of Egypt in the 1950s. The virus became recognized as a cause of severe human meningoencephalitis (inflammation of the spinal severe human meningoencephalitis (inflammation of the spinal cord and brain) in elderly patients during an outbreak in Israel in cord and brain) in elderly patients during an outbreak in Israel in 1957. The appearance of WN virus in North America in 1999, with 1957. The appearance of WN virus in North America in 1999, with encephalitis reported in humans and horses, may be an important encephalitis reported in humans and horses, may be an important milestone in the evolving history of this virus.milestone in the evolving history of this virus.

Equine death Equine death from viral from viral encephalitis.encephalitis.

Courtesy of CDC

• West Nile virus has been West Nile virus has been described in Africa, Europe, described in Africa, Europe, the Middle East, west and the Middle East, west and central Asia, Oceania central Asia, Oceania (subtype Kunjin), and most (subtype Kunjin), and most recently, North America. recently, North America.

• In the U.S. through July In the U.S. through July 2001, WN virus has been 2001, WN virus has been documented in Connecticut, documented in Connecticut, Maryland, Massachusetts, Maryland, Massachusetts, New Hampshire, New New Hampshire, New Jersey, New York, Jersey, New York, Pennsylvania, Rhode Island, Pennsylvania, Rhode Island, Florida, Georgia, Virginia, Florida, Georgia, Virginia, Ohio, and the District of Ohio, and the District of Columbia.Columbia.

Courtesy of CDC

Reduction of Mosquito Breeding Reduction of Mosquito Breeding Sites Sites

• Reducing the population of Reducing the population of mosquitoes, especially species that mosquitoes, especially species that are apparently involved with bird-are apparently involved with bird-to-bird transmission of WNV,to-bird transmission of WNV,such as some Culex species, can such as some Culex species, can help to reduce or eliminate the help to reduce or eliminate the presence of virus in a given presence of virus in a given geographical area.geographical area.

• The most important step any The most important step any property owner can take to control property owner can take to control such mosquito populations is to such mosquito populations is to remove all man-made potential remove all man-made potential sources of stagnant water in which sources of stagnant water in which mosquitoes might breed.mosquitoes might breed.

It is standing water like that shown It is standing water like that shown above that allows mosquitoes to above that allows mosquitoes to breed so prevalently.breed so prevalently.

Courtesy of CDC

• The natural transmission cycle of the virus involves a bird-mosquito cycle, but The natural transmission cycle of the virus involves a bird-mosquito cycle, but may include a tick-bird cycle where soft ticks (argasids) or hard ticks (ixodids) may include a tick-bird cycle where soft ticks (argasids) or hard ticks (ixodids) are found feeding on reservoir birds. The urban cycle of the disease requires are found feeding on reservoir birds. The urban cycle of the disease requires species of mosquitoes that will feed on free-ranging or domestic birds and species of mosquitoes that will feed on free-ranging or domestic birds and people.people.

• Local agencies must be prepared to use four fundamental approaches toward Local agencies must be prepared to use four fundamental approaches toward the management or control of these mosquito-borne agents: education, larval the management or control of these mosquito-borne agents: education, larval habitat source reduction, larval mosquito control and adult mosquito control, habitat source reduction, larval mosquito control and adult mosquito control, in that priority.in that priority.

• Prevention strategies Prevention strategies must be based on a must be based on a well-planned, area-well-planned, area-wide Integrated Pest wide Integrated Pest Management (IPM) Management (IPM) based program of based program of mosquito control. mosquito control. Some mosquito IPM’s Some mosquito IPM’s include surveillance, include surveillance, education, source education, source reduction, and larval reduction, and larval and adult mosquito and adult mosquito control.control.

Courtesy of CDC

• The foundation of any mosquito-borne disease control program The foundation of any mosquito-borne disease control program includes mosquito prevention, through source reductionincludes mosquito prevention, through source reductionand larval control, and an educational campaign. Human disease may and larval control, and an educational campaign. Human disease may be prevented in an IPM-based control strategy. Limiting mosquito be prevented in an IPM-based control strategy. Limiting mosquito populations before they become biting adults provides a margin of populations before they become biting adults provides a margin of safety, should a pathogen be introduced into an area. In addition, safety, should a pathogen be introduced into an area. In addition, larval control allows for the use of target-specific agents in definable larval control allows for the use of target-specific agents in definable areas, an environmental benefit over other methods.areas, an environmental benefit over other methods.

A collectionA collectionof mosquitoof mosquitolarvae in a pond.larvae in a pond.

Courtesy of CDC

Surveillance Data Interpretation. Surveillance Data Interpretation. • Bird and mammal surveillance data will be used by state and local agencies and institutions Bird and mammal surveillance data will be used by state and local agencies and institutions

responsible for disease control along with surveillance data from human case reports, human responsible for disease control along with surveillance data from human case reports, human surveillance testing, and mosquito testing. Municipalities that have had historical evidence of virus surveillance testing, and mosquito testing. Municipalities that have had historical evidence of virus activity need to monitor the larval and adult mosquito populations to allow determination of effective activity need to monitor the larval and adult mosquito populations to allow determination of effective timing and location of insecticidal and non-insecticidal control efforts.timing and location of insecticidal and non-insecticidal control efforts.

Mosquito Management: Mosquito Control by Non-insecticide Methods.

• Residential/Commercial Application: Residential/Commercial Application:

• Most larval control work on residential Most larval control work on residential and commercial properties must be and commercial properties must be done by the residents or owners done by the residents or owners themselves. themselves.

• It is the responsibility of government It is the responsibility of government agencies to advise them where agencies to advise them where mosquitoes breed, what mosquitoes look mosquitoes breed, what mosquitoes look like, and how to prevent breeding. like, and how to prevent breeding.

• Governmental agencies may provide Governmental agencies may provide assistance in conducting environmental assistance in conducting environmental sanitation efforts such as cleaning or sanitation efforts such as cleaning or flushing storm drains, removing tire flushing storm drains, removing tire piles; eliminating containers that may piles; eliminating containers that may hold stagnant water, etc.hold stagnant water, etc. A mosquito laying eggs.A mosquito laying eggs.

Courtesy of CDC

• Avoidance of adult Avoidance of adult mosquito bites by the mosquito bites by the general public. Minimize general public. Minimize time spent outdoors time spent outdoors between dusk and dawn. between dusk and dawn.

• Wear shoes, socks, long Wear shoes, socks, long pants, and a long-sleeved pants, and a long-sleeved shirt when outdoors for shirt when outdoors for long periods of time, or long periods of time, or when mosquitoes are most when mosquitoes are most active. active.

• Consider using mosquito Consider using mosquito repellent, according to repellent, according to directions, when it is directions, when it is necessary to be outdoors.necessary to be outdoors.

Mosquito Control Through the Use Mosquito Control Through the Use of Insecticidesof Insecticides

• Larvicides can be Larvicides can be used to control used to control mosquitoes in the mosquitoes in the aquatic stage before aquatic stage before they become biting they become biting adults. adults.

• This type of control This type of control generally has the generally has the least effect on non-least effect on non-target species and the target species and the environment.environment.

A picture of ‘wigglers.’ a common name used to A picture of ‘wigglers.’ a common name used to describe the young mosquito larval stage.describe the young mosquito larval stage.

Courtesy of CDC

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

• Microbial larvicides such as Bacillus thuringiensis varisraelensis and Bacillus sphaericus can also be used successfully in a broad range of freshwater habitats, but are somewhat more dangerous to use in salt marsh habitats.

Scanned image of West Nile virus isolated from brain tissue of a crow found in New Your. (Courtesy of CDC)

Courtesy of CDC

• Biochemical larvicides Biochemical larvicides (insect growth regulators - (insect growth regulators - IGRs) such as methoprene IGRs) such as methoprene can also be used in a variety can also be used in a variety of habitats, and are of habitats, and are especially effective in salt especially effective in salt marshes while expensive, marshes while expensive, solid, time-release pellets solid, time-release pellets and briquets can provide and briquets can provide sustained control in small sustained control in small areas, reducing labor costs. areas, reducing labor costs.

• Sustained release Sustained release methoprene products are not methoprene products are not for use in known fish for use in known fish habitats.habitats.

This is a female Anopheles mosquito feeding on a person. Only the female mosquito feeds on blood. Notice how the body of this mosquito is held at an angle to the skin.

Courtesy of Mr. Todd Burgess

• Mosquito adulticides should be considered the least desirable Mosquito adulticides should be considered the least desirable method of control and only used when currentmethod of control and only used when currentisolations of virus and/or evidence of disease has been isolations of virus and/or evidence of disease has been established.established.

• Currently available adulticides include organophosphates, Currently available adulticides include organophosphates, pyrethrins, and pyrethroid-based insecticides. These may be pyrethrins, and pyrethroid-based insecticides. These may be applied by backpack or truck foggers, or fixed-wing aircraft.applied by backpack or truck foggers, or fixed-wing aircraft.

Follow Up Activity: Follow Up Activity: HomeworkHomework

• Construct an IPM for our high school that includes how Construct an IPM for our high school that includes how you can specifically implement what was discussed in the you can specifically implement what was discussed in the presentation to our school. Be sure that the IPM is presentation to our school. Be sure that the IPM is directed at eradicating mosquitoes on and near the directed at eradicating mosquitoes on and near the school property. Use the links below to help you school property. Use the links below to help you research your IPM.research your IPM.

• http://schoolipm.ifas.ufl.edu/http://schoolipm.ifas.ufl.edu/

• http://ipmwww.ncsu.edu/http://ipmwww.ncsu.edu/

• http://www.reeusda.gov/agsys/nipmn/index.htmhttp://www.reeusda.gov/agsys/nipmn/index.htm