What does the District use to control adult mosquitoes?

Adult mosquito control is conducted when all other methods of control have been exhausted or when larval control measures are unsuccessful or not possible. Most importantly, it is used for the quick knockdown of adult mosquitoes to break the disease transmission cycle.

The District uses products containing pyrethrins for adult mosquito control. Pyrethrins are a group of naturally occurring compounds with insecticidal properties that are extracted from chrysanthemum flowers. When formulated, pyrethrin is used as an adulticide to target flying adult mosquitoes. Pyrethrins are widely used for control of various agricultural, public health, and nuisance pests.

The materials are applied in an Ultra Low Volume (ULV) form, similar to a fog. The tiny (micron-sized) pyrethrin particles impinge on flying mosquitoes. Pyrethrin affects the nervous system of insects by causing multiple action potentials in the nerve cells by delaying the closing of the ion channel. Pyrethrin formulations usually contain a synergist, piperonyl butoxide, which restricts an insect enzyme used to break down toxins. Pyrethrin based adulticides are labeled for use in both agricultural and residential areas for the quick knock-down of adult mosquitoes.

The Environmental Protection Agency (EPA) has determined that pyrethrin-formulated adulticides, when used at labeled rates for mosquito control does not pose unreasonable harm to the environment or humans. Label rates for mosquito control are normally less than one ounce per acre. Pyrethrins are extremely photosensitive and break down within hours in the sunlight. People with chemical sensitivities could experience eye and skin irritation or an allergic type reaction if exposed to a pyrethrin formulated adulticide application.

All products used by MSMVCD are EPA registered public health pesticides labeled for mosquito control. Applications of these products are conducted by state certified mosquito and vector control technicians in accordance with label requirements and limitations. Click here to view all labels and Material Safety Data Sheets (MSDS) for the pesticides used by the District.

For more information on materials registered for mosquito control, visit the Centers for Disease Control (CDC) website.