Plymouth County Mosquito Control Project
Plymouth County Mosquito Control Project
The Project's activities fall into six categories
2. Larval Site Identification:
Project personnel identify and catalog suspected mosquito
breeding sites. Once a site has been proven to breed mosquitoes, a decision is
made on how to best treat the site and it will become part of the Site
Reduction Program or the Larviciding Program. The data recorded for each site
include: directions to the site, dates of site inspections, results of each
observation (if mosquito larvae are found – species, number/dip, and stage of
development), and what action was taken (was the site treated).
Breeding site reduction is the most effective strategy for
reducing mosquito populations. This strategy may require hand-clearing a
clogged stream or even the use of heavy digging equipment to remedy the
The Project does not drain wetlands and will only clear or
dig on sites that have been confirmed to breed mosquitoes. Restoring the flow
of a small stream or removing a blockage in a drainage ditch are examples of
appropriate Project activities in the Site Reduction Program.
Winter Site Reduction Work:
Winter is a busy time for the Project doing site reduction
work such as hand clearing streams and using the excavator to do ditch work.
Open Marsh Water Management (OMWM)
An important part of the breeding site reduction program is
Open Marsh Water Management (OMWM). This technique is used only on salt
marshes. OMWM was originally developed in New
Jersey and is considered to be an environmentally sensitive alternative
to grid ditching salt marshes. OMWM holds water on the marsh, improves fish
habitat and reduces evasive vegetation.
The heart of most OMWM projects is the creation of ponds on the marsh
that can be used by small fish and wading birds. Ditches from the pond to areas
that produce mosquitoes allow the fish to eat the mosquito larvae when they are
present. OMWM is an important tool in areas where the goal is restoration as
well as mosquito control.
Larviciding is the second most effective strategy for
reducing mosquito populations. Most breeding sites are not appropriate for the
site reduction strategy and as a result, larviciding is the Project’s primary
strategy for controlling mosquito populations.
The Project uses
a variety of equipment to larvicide areas that produce mosquitoes. A Project worker using a hand-held pump can
treat small sites. Sites may also be treated using a specially equipped truck.
This vehicle has a hydraulic sprayer and over 300 feet of hose, which enables
it to treat most large breeding sites.
However, most larviciding is done in the spring through the use of
aircraft. Using aircraft we treat
approximately 10,000 acres each year.
thuringiensis israelensis), a biological insecticide, is the primary material
used in the larviciding program. It is the only product used in our aerial
While listed sixth on this page, the placement does not
reflect the priority level we place on public education. We believe that education is our top
priority. In fact, most of our website is dedicated to education. You will find information about pesticides,
repellents, mosquito life cycle, mosquito borne diseases (West Nile Virus,
Eastern Equine Encephalitis, and dog heartworm), controlling mosquito breeding
around the home, important state regulations, and links to mosquito information
and education websites. Additionally, we
provide speakers for schools, community organizations, and civic groups. We also have attempted to provide the schools
of Plymouth County with opportunities for bringing mosquito education into
their classrooms and connect it to the Massachusetts Curriculum Frameworks.
Plymouth County Mosquito Control Project works closely with
the Massachusetts Department of Public Health (DPH) to monitor West Nile Virus
and Eastern Equine Encephalitis Virus activity and to help determine the level
of human risk. The Project runs traps for adult mosquitoes in areas we consider
likely to have virus activity in mosquito populations. The mosquitoes collected
are sent to the Department of Public Health (DPH) and tested for mosquito borne viruses.
Since no method of mosquito control is 100% effective, the Project sprays for adult mosquitoes.
Project personnel spray for mosquitoes, using trucks, between the hours of 2:00am and a half hour before sunrise, Monday through Friday. The Project uses ultra low volume (ULV) sprayers, which allows minimal amounts of pesticide to be used.