In summer mosquito fight, Suffolk County says it's ready for battle

Blood-hungry, disease-carrying mosquitoes, as much a part of a hot, sticky Long Island summer as a Mister Softee jingle or a day at Jones Beach, are back for the season and looking to bite. 

But the buzzing of helicopters above Tuesday, spraying a mix of larvae-killing pesticides on some East End marshes below, also signaled the return of a worthy adversary: Suffolk County Vector Control.

Vector control crews sprayed two pesticides — one considered by environmental experts as a danger to certain marine life — on marshes at Lyman Marsh, Smith Point County Park and the Wertheim National Wildlife Refuge in Brookhaven; Napeague and Beach Hampton in East Hampton; and the West Oak Recreation Club in Islip. It was Suffolk's fourth mass spray of the year — an effort that began June 11.

Health hazards

Mosquitoes found in salt marshes like those targeted Tuesday are not as likely to transmit West Nile virus as other species, said Suffolk vector control director Tom Iwanejko in an email. However, he noted, they are “highly capable” transmitters of Eastern Equine Encephalitis, which the Centers for Diseases Control and Prevention describe as a “rare but serious disease.”

Mastic Beach and South Shirley residents "call us to complain they must literally run to their car or mailbox and still get tons of mosquito bites," Iwanejko said.

The health hazards can be seen when they "send us pictures of their children with their eyes swollen shut from mosquito bites after returning from the hospital due to their child's severe allergy to the mosquito bites," he said.

Following full and new moon tides or major storm events, or about every two weeks starting in May and continuing through September, the vector control crews sample water at 2,500 acres of marshland spread across approximately 70 sites, Iwanejko said.

"Only if the site is breeding larval mosquitoes," he said, "do we consider aerial application of the marsh."

Spraying from above

Pesticide-spraying helicopters are a key component of Suffolk's seasonal mosquito wars, sometimes with the help of volunteers who pinpoint the marshes and wetlands used most often as breeding grounds, officials said.

Volunteers trained by Suffolk County Vector Control and The Nature Conservancy step up each summer in East Hampton during what are called "Marsh Mondays," said Kim Shaw, the environmental protection director for the Town of East Hampton. For several years, volunteers have collected water samples in Accabonac Harbor, counted larvae and sent data to Suffolk vector control to pinpoint areas for pesticide use.

"Mosquitoes are a real problem, especially along the Napeague stretch with all the large freshwater wetlands," Shaw said. "Restaurants down there have a heck of a time battling that with outdoor dining."

Iwanejko said spraying targeted areas identified by volunteers "significantly" cut down the county’s pesticide use in Accabonac Harbor. Wetland restoration projects, such as those undertaken at both the Wertheim and West Sayville national wildlife refuges, which bolstered killifish populations in marsh waters to eat mosquito larvae, also resulted in reduced pesticide usage.

Environmental impact

Environmental advocates have long railed against the use of methoprene, one of the two pesticides the county employs to spray mosquitoes, arguing it harms larval crustaceans.

Suffolk sprays a combination of two pesticides — Bacillus thuringiensis israelensis, also known as BTI, and methoprene — to kill mosquito larvae at different stages of development.

BTI poses no environmental threat and is even "used by organic farmers," said Adrienne Esposito, the executive director for Citizens Campaign for the Environment. But methoprene, Esposito said, can be detrimental to marine life, such as blue claw crabs and other local shellfish that spawn in salt marshes.

"Wetlands are a critical habitat for shellfish and finfish," she said. "We need the county to be very careful and very judicious about the use and potential abuse of this pesticide."

In Suffolk, Iwanejko said, methoprene “is also only used in the upper high marsh and not broadcast in the intertidal marsh or out in the bay, further reducing potential contact with blue crabs and shellfish.”

He added that Stony Brook Marine Science Center researchers reviewed methoprene and "found it was an accepted material" for the county’s purpose, and the pesticide "has undergone rigorous" federal and state review.

Officials and environmental advocates agreed that pesticide use has come a long way in recent decades.

"It’s not like the old days where there was a fogging truck going down the street and kids were riding their bicycles after it," Shaw said of past efforts to reduce the mosquito population.

Esposito said pesticides have become "less toxic" in recent years, but must still be used with caution.

"Twenty years ago, Nassau and Suffolk used to spray liberally all the time," she said. "They have really reeled that back. They’ve become more sophisticated in their methods . . . and I think that has really helped the environment and helped the public."