Below you will find descriptions of the pesticides most commonly used at Plymouth County Mosquito Control Project. We have also included their labels and safety data sheets.
Larvicides are products that kill immature mosquitoes (larvae). They are applied to water only when mosquito larvae have been found. PCMCP has mapped over 3,500 sites that frequently contain mosquito larvae. As part of our program we monitor and treat those areas on an as needed basis. If new sites are found they are also mapped and added to our program.
Bacillus thuringiensis israelensis (Bti) is a biological pesticide and is from a soil bacterium that was discovered in Israel in 1977. Bti has been used in mosquito and blackfly control for many years. The insecticide is created when the bacterium Bti is placed in unfavorable conditions it hardens and forms spores. Within these spores is a parasporal body comprised of proteins. These proteins have insecticidal properties. When a mosquito larva ingests the Bti portions of the mosquito's gut rupture, killing the larva. When we use Bti to control mosquitoes the bacteria is dead and no live organisms are released into the environment.
Bti is specific to mosquitoes, blackflies and midges. It breaks down quickly in the environment and is essentially non toxic to other insects, humans and other mammals.
Below is a list of products that PCMCP uses along with their Safety Data Sheets and labels.
Bacillus sphaericus (Bs) is similar to Bti. It is a common soil bacterium. Mosquito larvae die when the bacterial spore is ingested. The spore contains proteins that damage the gut of the larvae. The product can be effective for several weeks unlike Bti. Bs is most effective against Culex mosquitoes. The insecticide is used in water with high organic content such as catch basins.
Below is a list of Bs products that PCMCP uses along with their Safety Data Sheets and labels.
Methoprene is a growth regulator and prevents the immature insect from developing normally. The insecticide mimics juvenile hormone. Juvenile hormone has several functions within an insect. If the hormone is present when the larva molts the insect will remain a larva. If the hormone is absent the larva will become a pupa and begin to develop into an adult insect. Since methoprene mimics juvenile hormone the larva is prevented from developing into an adult.
Plymouth County Mosquito Control uses methoprene mainly in two situations. We use the insecticide in catch basins to control the mosquitoes responsible for transmission of West Nile Virus. We also use the chemical in areas that will produce mosquitoes repeatedly throughout the summer.
Adulticides are products that are designed to kill adult mosquitoes.
Duet - Duel Action Adulticideis a synergized synthetic pyrethroid consisting of 1% Prallethrin (ETOC), 5% Sumethrin, 5% Piperonyl Butoxide, and 89% other ingredients such as mineral oil. Duet's EPA Reg. No. is 1021-1795-8329. The product breaks down quickly when exposed to sunlight. Therefore residue on plants and other treated surfaces should be short lived. Plymouth County Mosquito Control applies this chemical using truck mounted ULV (ultra low volume) sprayers. The Project uses an application rate of 0.62 fl oz per acre.
Initial field trial and cage trial observations have shown that DUET causes “benign agitation” – a non-biting excitation of mosquitoes. Benign agitation has the potential to draw mosquitoes from a resting state – possibly including mosquitoes never before factored into efficacy calculations -- into on-the-wing activity. When mosquitoes are flying rather than resting, more of the spray comes in contact to kill them.
Mavrik Perimeter is used as a perimeter treatment. The purpose of this treatment is to exclude mosquitoes from an area. The active ingredient is the pyrethroid tau-fluvalinate. The pesticide is applied as a liquid to vegetation, soil and structures around the area. Mosquitoes are killed when they land on treated surfaces. The application can last several weeks. PCMCP uses this product in public areas such as ball fields.