CRANBERRY ISLES — Mosquitoes have been driving residents of the Cranberry Isles crazy for at least a century. But the swarms likely will return this summer, because residents rejected a proposal to address the biting bugs.
At their annual town meeting on Saturday, March 16, residents voted down the plan to introduce a bacterium that would have killed the mosquito larvae.
Reached by phone after the meeting, select board chairman Richard Beal said the Cranberries’ large fishing community wants to wait until there is more definitive data about the bacterium and its relationship to lobsters. He said some fishermen offered to pursue further studies on Bti safety.
The proposal to control the pests, priced at $25,000 for the first year, would have deployed thee naturally occurring bacterium called Bacillus thuringensius israelensis (Bti) in salt marshes, cattail marshes and stagnant waters.
In August, selectmen heard from Islesford resident Joseph Delafield who submitted a petition from over 90 residents of Islesford that requested the town undertake as soon as possible a program of mosquito control “in the interests of public health and safety, economic wellbeing, and citizen comfort.”
In an interview last month, Beal said the mosquitoes were particularly vicious last summer.
Petitioners and town officials had agreed on a plan of attack, but also wanted to ensure that a control program do no harm to lobsters and fishing in general.
Delafield has been a summer resident of Islesford for 50 years; his wife has lived there since childhood. Some areas, he said, are enveloped by clouds of mosquitoes; the bites are vicious enough to cause bleeding sores for some.
Petitioners were concerned about the risk of West Nile virus and eastern equine encephalitis, and about the insect’s effect on tourist traffic.
It’s not a new problem.
According to the town’s 2002 mosquito study, the Cranberry Isles were extensively ditched and drained in 1928 in an effort to control mosquitoes. A 1928 newspaper article quoted Major Edwin Skinner, the mosquito-control expert who led the project, who explained why the Cranberry Isles contain “the most prolific mosquito breeding, in proportion to their area, of any section in the Eastern States. This is primarily due to the fact that the ocean has thrown up great stone and sand sea walls. Through these the perigree tides seep or overflow the boundaries, thus leaving pools and ponds of salt water that soon stagnate and breed millions of mosquitoes.”
“Many of the ditches are now clogged and themselves serve as breeding pools for mosquitoes,” the 2002 study said.
The 2002 study came about when the town reopened the matter after two particularly bad summers and in light of the then-recent arrival of West Nile virus in Maine. Voters subsequently considered but rejected the use of larvacides in breeding areas.
Through Delafield’s research, the town identified pest management company Swamp, Inc., of Kittery, to provide specifications on the how a control effort might be accomplished. Swamp entomologist Michael Morrison, as well as Maine Board of Pesticides Control pest manager Gary Fish, said that Bti is nontoxic to lobsters.
In his proposal, presented to the town in December, Morrison said Bti has been used successfully for many years. And he said wetlands management should also be part of the program.
But, for now anyway, the plan is on the shelf.