For many years, Portsmouth, New Hampshire was the northernmost
outpost of community mosquito control along the east coast. In
1994, a mosquito control program in Maine was started at Gerrish
Island in Kittery. I am presenting a history of mosquito control
in Maine based upon conversations with various communities, the
Maine Board of Pesticides Control, the Maine Department of Environmental
Protection (MDEP), and my personal experiences.
Maine has a three thousand seven hundred mile coastline with sixteen
thousand five hundred fifty- five acres of saltmarsh. Although
the coastline is predominantly rocky, there are extensive areas
of riverine and estuarine ecosystems. The most common wetland
type is red maple swamp. The most common anthropophilic mosquito
species are two saltmarsh mosquitos (Aedes cantator Coquillett
and Aedes sollicitans Walker); snowmelt Aedes spp.(vernal
and red maple swamps); Aedes vexans Meigen; and Coquillettidia
perturbans Walker.
The earliest evidence of mosquito control in Maine is from the
southern coastal town of Wells. The Wells Chamber of Commerce
started a dragonfly nymph mosquito control program in 1975. Nymphs
were imported from a Massachusetts biological supply company.
Residents purchased the nymphs at the Chamber offices and were
instructed to place them in waters adjoining their properties.
The nymph program became a huge public relations attraction with
articles appearing in several national magazines. Inquiries were
received from all over the world. The nymph program is still in
existence and is advertised each spring. I wrote the Chamber in
1986 regarding the nymph program. The response I received stated
that scientifically there is no way to measure the results and
that residents are very vocal in support for the nymph program.
The York County Coast Star (newspaper) stated on April 9, 1986
that there has been many doubts raised over the years about the
effectiveness of the nymph program, but residents and others who
religiously order the nymphs are expected to remain loyal and
reorder more. The newspaper article stated that the Chamber has
been investigating the possible use of BTI, but in the meantime
are going to stay with the nymphs.
Vectobac G, a BTI insecticide, was tested in Georgetown (mid coastal
Maine) in the mid 1980's. When testing was completed, the town
funded a BTI program with Vectobac to continue controlling three
thousand acres of saltmarsh. A helicopter was equipped with a
granular applicator and hand operated granular applicators were
also utilized. The program did not last long for reasons I could
not identify.
In 1990 I was invited by the City of Portland to investigate a
possible mosquito control program on Cliff Island. Portland has
an archipelago in Casco Bay. The islands are part of Portland
and receive services from the city. Cliff Island is a seasonal
vacation spot with three hundred permanent residents. I visited
the island via a World War II landing craft that provides garbage
removal for all the islands. Cliff Island is ten miles from the
city and several miles from the nearest island. The island has
a granite ridge about one mile long and a quarter of a mile wide.
A lowland area extends from the ridge and has a nine acre cattail
marsh and a fifteen acre abandoned cranberry bog. The cattail
marsh is susceptible to saltwater flooding during storm tides.
Aedes cantator and Aedes vexans have been collected from the cattail
marsh. Aedes canadensis, Aedes excrucians, Aedes communis, and
Aedes abserratus have been collected from vernal pools. I revisited
the island in 1991 and presented a mosquito control program. My
visit was well received and interest in BTI was strong. I have
not been able to pursue the Cliff Island program but I plan to
in 1995. Other islands have shown interest.
In 1993 1 was approached by the Gerrish Island (Homeowners) Association
of Kittery, Maine. Their mosquito problem is legendary. The island
is two miles long by two miles wide. The saltmarsh is flooded
by tidal waters from Chauncey Creek. A seawall prevents direct
flooding from the Atlantic Ocean. The saltmarsh was grid ditched
but the system has failed. The interior of the island has a twenty
acre red maple swamp and a seven acre shrub swamp. There are numerous
vernal pools in the spring. I have collected mosquito larvae from
Gerrish Island between 1990 and 1993. 1 discovered that saltmarsh
mosquitos (Aedes cantator and Aedes sollicitans)
and freshwater mosquitoes (snowmelt Aedes spp. and Aedes
vexans) are the predominant pests during each season.
The licensing process for a mosquito control program at Gerrish
Island began in October of 1993. Funding was secured from the
Gerrish Island Association and local property owners were notified
for access permission. The license application supplied by the
Maine Department of Environmental Protection (MDEP) required detailed
information on target mosquito species and wetland areas to be
larvicided. There had been no mosquito control license issued
by the MDEP for ten years. The license is called a Wastewater
Discharge License and is sought by wastewater treatment plants
and paper mills, also. A simplified application was designed by
the MDEP since the previous application had many conditions not
related to mosquito control. I was told by the MDEP that the most
important part of the application was to describe the need for
using a pesticide, economic considerations and the impact upon
non-target species. The application fee was $195.00 and the license
is good for five years.
The license was issued by the MDEP in April of 1994 after six
months of communications between myself and MDEP biologists. MDEP
was very helpful and careful in assuring the license application
was accurate. MDEP listed "findings of facts" regarding
the license. They stated that the discharge (BTI application)
would not lower existing water quality; will not have a significant
impact upon non-target organisms, existing wildlife, or plant
uses; and will not result in significant degradation of the human
uses of the receiving water. MDEP further stated that the discharge
is necessary to allow citizens of Gerrish Island to make full
social and economic use of their properties and that there are
no practical or economically feasible alternatives to spraying
for mosquito control.
In summary, the MDEP is very cautious in approving mosquito control
license applications. Conventional larvicides would most likely
not be approved for discharge licenses. BTI is approved by MDEP
biologists but only after close scrutiny. The Gerrish Island discharge
license has proven to be a time consuming ordeal. Future discharge
licenses should be much easier now that I know exactly what information
is required.