News Flash


Posted on: October 1, 2019

Aerial Mosquito Spraying FAQ

Mosquito-borne illness

Union County Mosquito Control is planning to treat all of Berkeley Heights via aerial spray in response to address the recent EEE activity found in Berkeley Heights. The spraying, still subject to approval by the Federal Aviation Administration (FAA), will be carried out by a State of New Jersey, Department of Environmental Protection contracted helicopter. A date is still to be determined; it is heavily dependent upon weather in the near future. The County continues to trap and send mosquito pools in for testing; all recent tests have come back negative for EEE, West Nile and other mosquito-borne illnesses. 

Meanwhile, here are a few FAQs to help answer resident concerns.

Q. When will the aerial spraying take place?

A. The township is currently awaiting approval from the Federal Aviation Administration (FAA); it may happen tonight (Wednesday, Oct. 2). We will alert residents via the electronic billboard downtown, email (if we have your email address), phone call (if you signed up for our Swift 911), on our website and on our Township Facebook page.

Q. What time will the spraying start?

A. 7-10 pm on the date approved by the FAA; date is still pending approval.

Q. Why is the spraying happening at 7 pm and not later at night?

A. This is the time of day when mosquitoes are most active; they have to fly through the adulticide droplets in the mist being sprayed in order to be affected.   

Q. What is the chemical used and is it dangerous?

A. The spray used is known generally as an “adulticide,” and it stops working on mosquitoes once it hits the ground. This specific product that will be used, Duet HD, combines two active ingredients – Sumithrin and Prallethrin. It causes fast knockdown and causes resting mosquito to take flight, so the spray can take effect. Duet is the most handler-friendly aerial adulticide formulation on the market. There is no offensive odor, it is a non-corrosive formulation, and it only takes a half an ounce per acre to be effective. 

According to the World Health Organization, Prallethrin is used in household insecticide products against mosquitoes, houseflies and cockroaches, and also has veterinary uses in the treatment of domestic pets. Prallethrin is of low mammalian toxicity, with no evidence of carcinogenicity.

Sumithrin® has been registered by the EPA since 1976 for use to control adult mosquitos and other nuisance insects indoors and outdoors in residential yards and public recreational areas. It is in one of several synthetic pyrethroids commonly used in mosquito control programs to kill adult mosquitoes. Applications are used to control mosquitoes over agricultural as well as non-agricultural areas. Sumithrin is an ingredient similar to the natural components of the chrysanthemum flower, which is also found in other pesticide products used indoors, in pet shampoos, and tick control treatments. Sumithrin is rapidly inactivated and decomposes with exposure to light and air, with a half-life of less than one day in the air and on plants. In soil, it degrades rapidly. These types of pyrethroids can be used for public health mosquito control programs without posing unreasonable risks to human health, wildlife or the environment when applied appropriately. When applied according to label directions, pyrethroids used in mosquito control programs do not pose unreasonable risks to wildlife or the environment. Pyrethroids are low in toxicity to mammals and are practically nontoxic to birds.

Q.  Should we remain indoors during spraying?

A. The adulticide stops working on mosquitoes once it hits the ground. Although the township, Board of Education and other sports organizations will cancel all nighttime activities after 7 pm due to the spraying, that is out of any concern parents may have with their kids being outside during the spraying, not because the spray is harmful to them. It is entirely a personal choice whether to remain inside during spraying.

Q. Should we close our windows and turn off our air conditioning during spraying?

A. This is entirely a personal choice, based on the information provided above, as well as in the accompanying flyer about Duet.


The New Jersey Department of Health recently confirmed two new human cases of EEE in Union and Atlantic counties. The Department confirmed the first human case, located in Somerset County, in August. This July, the Department of Health launched its Fight the Bite NJ awareness campaign to continue to promote awareness and provide education throughout the state on how to avoid mosquito-borne illness. Please visit that website for more preventative measures you can take to protect against mosquito bites.

Please see below for more information about Duet Adulticide. 

Duet FAQ2 Jpg_1

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