Mosquito Control Programs in Massachusetts

Historically and to the present day in Massachusetts, the desire to control mosquitoes was driven by an interest to reduce a summertime nuisance that impacted the quality of life for citizens of Massachusetts. During the 1930s to 1950s, many public works efforts revolved around draining freshwater and salt water wetlands to control mosquitos. Today in Massachusetts, with more focus on protecting wetlands, the motivation to control mosquito populations has shifted primarily by the desire to control to potentially fatal human diseases like West Nile Virus and Eastern Equine Encephalitis (EEE). While the West Nile virus is a statewide problem that originated with the entry of the disease in Massachusetts in the mid-1990s, EEE on the other hand, is a concern mostly in Southeastern Massachusetts (the Buzzards Bay watershed), particularly in Plymouth, Bristol, and Norfolk counties.

There are two broad categories of mosquito control programs for which we receive inquiries: large scale spraying programs with pesticides or bacterial agents to control mosquitoes over larger areas, and the older, but still existing program of maintenance of salt marsh drainage ditches and various other management practices. The Mass.gov website Mosquito Control and Spraying provides information about spraying and mosquito control programs in Massachusetts. Below are additional links for more information about these state and local efforts in Massachusetts.

Bacterial and pesticide Spraying

The Massachusetts Health and Social Services is one of the lead organizations in Massachusetts that makes decisions about managing mosquito populations that are a threat to human health. Detailed information about their efforts can be found at this web page. In a practical sense however, it is the State Reclamation and Mosquito Control Board that implements most efforts to control mosquito populations in Massachusetts.

There are two broad types of spraying strategies to control mosquito populations. Strategies to control the water living mosquito larvae (“larviciding”) involves the application of chemicals or bacterial products to mosquito breeding areas to kill or inhibit the growth of mosquito larvae to the adult form. Strategies to control adult mosquitoes (“adulticiding”) generally involve the wide scale application of pesticide chemicals to kill the adult form of the mosquito. These are applied by truck-mounted sprayers, planes, or helicopters.

SRMCB and Maintenance of Salt Marsh Ditches

The State Reclamation and Mosquito Control Board (SRMCB) is an organization under the Massachusetts Department of Agriculture, that was established by Chapter 252 of the Massachusetts General Laws (“improvement of low land and swamps”) and other special legislation (Acts and Resolves). The Board is broken into nine Mosquito Control Projects and Districts that roughly fallow County lines. One of the objectives of the board is to “to eradicate mosquitoes in any area infested thereby.” The law also gives municipal boards of health broad legal authority to declare any area infested by mosquitoes, or likely to produce mosquitoes within the limits of any such city or town or of such district, as a public nuisance.

The SRMCB personnel use and integrate variety of mosquito management strategies to suppress mosquito populations including: surveillance, salt marsh ditch maintenance, open marsh water management, larviciding, adulticiding, catch basin management, biological control (release of mosquito eating fish), and public education about draining standing water from manmade objects.

While mosquitoes in salt marsh are not known to carry either West Nile of EEE, the SRMCB continues to maintain existing salt marsh ditches. These activities are exempt from the state wetlands protection act and local bylaws. Some tidally restricted marshes in Buzzards Bay identified in our salt marsh atlas were restored because the SRMCB removed fill that had accumulated in a salt marsh drainage ditch.