Town Trustees Debate Methoprene With Suffolk County Vector Control

Dominick Ninivaggi, the superintendent of Suffolk County Vector Control, defended the use of methoprene to control the mosquito population at a meeting with the Southampton Town Trustees on Monday.

While the type of mosquito that carries the Zika virus, Aedes aegypti, is not found in New York State, a related species, Aedes albopictus, is, and scientists have not been able to determine if that mosquito can carry the virus. Mr. Ninivaggi said Long Island is near the northern boundary of the albopictus mosquito’s range, and that his division was watching the situation closely.

Mr. Ninivaggi discussed methods the county uses to control the mosquito population, in fresh water primarily with larvicides like Bacillus thuringiensis subspecies israelensis, or BTIs, and in marshlands by spraying methoprene.

He said BTIs work well in controlling the mosquito population as long as the mosquito larvae eat the BTI particles, explaining that the Zika-bearing larvae are commonly found in standing water, where this is more likely to occur.

As far as controlling other mosquito-borne diseases like West Nile virus, the county typically turns to spraying marshlands with methoprene, a controversial practice that Mr. Ninivaggi defended vigorously. He told the Trustees the county sprays above the high water mark, which is land that does not fall under the Trustees’ jurisdiction. He also said New York State has some of the strictest regulations when it comes to spraying for mosquitoes, and that methoprene was not used in New York until the mid-1990s, when other coastal areas in the country were using it since the 1970s.

“No pesticide is perfect,” he said. “No pesticide has absolutely no impact on anything else.”

When the Trustees asked whether methoprene has hurt lobster and shellfish populations, Mr. Ninivaggi dismissed the question, saying no scientific evidence has been provided to prove this, and that they are not closely related to mosquitoes given that they diverged from each other in their evolutionary paths more than 250 million years ago.

But according to Kevin McAllister, founder of the Sag Harbor-based group Defend H20 and a former Peconic Baykeeper, who was also at the meeting, the larvicide can inadvertently harm other insects and crustaceans, like juvenile blue claw crabs, that live in the habitats typically targeted by the spraying and that are genetically similar to mosquitoes.

Mr. McAllister has been trying to raise awareness among county officials about the larvicide’s effects on the marine environment since 2007, when the countywide mosquito spraying plan was first put into place. That program, dubbed the Suffolk County Vector Control and Wetlands Management Long-Term Plan, relies on spraying methoprene in wetlands across the East End.

Mr. McAllister pointed to a Connecticut ban on the use of methoprene in any storm drain or conveyance for water within the coastal boundary unless the population of that municipality is greater than 100,000. He went on to say that New York City banned the use of methoprene in Jamaica Bay in 2001.

Mr. Ninivaggi told Mr. McAllister that if there is new information people should feel free to submit it to Vector Control to review.

After sitting through the presentation and line of questioning, Trustee Eric Shultz said the issue needed to resolved, because baymen are convinced that methoprene has hurt shellfish populations. Mr. Shultz suggested that Vector Control go out on the water with baymen a day after spraying, to check the levels of methoprene in shellfish—to which Mr. Ninivaggi replied that his division does not have the funding to be able to take part in such an activity.