NYC and NJ Pit Crustaceans Against Mosquitoes

Ah, summer. With the season comes hot days in parks and evenings brightened by fireflies. But with summer also comes the inevitable buzz-kill: the mosquito bite.

How to combat mosquitoes is a constant discussion in households, in the halls of government and in science labs. In New Jersey, scientists have found their answer in tiny crustaceans.

This copepod, created in a New Jersey Department of Agriculture lab, was later released in Cape May County. Photo courtesy of the NJ Department of Agriculture.

The labs are the new breeding grounds of copepods, a distant relative of another symbol of summer — the lobster. These are the not-so-natural-born killers that are being used to fight mosquitoes in New Jersey.

At a lab in West Trenton, scientists in the state  Department of Agriculture’s Phillip Alampi Beneficial Insect Rearing Laboratory bred a colony of naturally occurring copepods, which look like tiny shrimp with long antennae and are approximately 1 to 2 millimeters in length.

“We colonized thousands at a time. They grow in water. You can have several thousand copepods in a bucket,” said Bob Kent, administrator of the state Office of Mosquito Control.

Mosquitoes lay eggs in standing water, so copepods are being released into places where standing water collects — in tires, containers in backyards and junkyards, at construction sites and in road-side ditches.

Copepods bred in a laboratory are released into a roadside ditch in Cape May County, New Jersey. Photo courtesy of the NJ Department of Agriculture.

New Jersey began combating mosquito larvae (eggs) with copepods last year, Kent said. In late June 2012, 10,000 copepods were released in Cape May County, following the previous release of 50,000 copepods in Bergen, Passaic and Morris counties.  More are on the way.

“We are transferring them to containers and overtime the population will grow,” said Kent.

State and county Mosquito Control workers will release the copepods into residential and commercial areas.

Copepods reproduce on their own and are found around the planet, primarily in wetlands and bogs and water without a strong current. They feed on mosquito larvae. New Jersey is only the second state in the United States to test their efficacy in combating mosquitoes, said Kent. The first was Louisiana, and in fact, an expert from the state visited New Jersey to coach them on using the tiny crustaceans.

While Kent says copepods are a “no brainer” for New Jersey, the crustaceans that were studied in New York City in 2010 and 2011 were ultimately never used.

“Copepods are not very effective for control of mosquitoes in our environment,” said Dr. Waheed Bajwa, executive director of Vector Surveillance at the New York City Department of Health.

“We went to different areas and collected them and tried to breed them and looked at their efficacy.”

If you’ve seen one copepod, you haven’t seen them all. There are 13,000 species of copepods, but only if they exist naturally in an area can they be reproduced and counted upon to reliably attack that area’s mosquito larvae. According to a study conducted by Dr. Jorge R. Rey and Dr. Sheila O’Connell, professors in the Entomology and Nematology Department at the Medical Entomology Laboratory at Florida State University, not all copepods are effective at controlling mosquito populations, and some are better than others.

“Some species are not particularly good predators, and some are,” said Rey, whose lab provides mosquito/copepod rearing kits to Florida teachers for use with their students.

Bajwa said and Rey concurred that introducing a non-native species of copepod to New York City was not in the city’s best interest.

Copepods have never been used or tested in any other part of New York state, according to John Emery, a spokesperson for the state Department of Health.

But they have shown up in the city’s water supply, which comes from reservoirs upstate.

In 2010, a user on the internet forum Reddit posted a picture of copepods he’d spotted in his tap water. The story went viral, with both Time Magazine and Gizmodo picking it up, and even resulted in segments of New York’s Jewish population raising concern about whether New York City’s drinking water was kosher. (Copepods are shellfish, which is not a kosher food.)

“It’s one of those interesting facts you learn about local drinking water — but it’s in no way dangerous,” Farrell Sklerov, a spokesman for the New York City Department of Environmental Protection (DEP), told at the time.

The same is true today, said Mercedes Padilla, a current spokesperson for the DEP: The creatures do exist in the city’s drinking water, but they are harmless. According to spokesperson Edward Timbers at the DEP, midge fly larvae have also been found in NYC drinking water at times.

New York City’s mosquito control relies on both larviciding and adulticiding. In the former tactic, larvicide, which attacks mosquito larvae, is sprayed over wetlands and swamplands from a helicopter. The latter, which combats adult mosquitoes, is achieved through spraying pesticides from backpack tanks. Bajwa said residential spraying, which is done at night, is only conducted if there is a threat in the area. The Department of Health is constantly testing for West Nile Virus, and if it is found, the entire area is treated. So far this year, three cases of West Nile Virus have been found. All were on Staten Island.

Contrary to wide-spread belief that there will be more mosquitoes this summer because of the unusually warm winter, Bajwa said so far that has not been the case.

“Looking at data collected this year and last year, there is no significant difference,” he said.

He did, however, add that there is always more that can be done to combat the biggest annoyance of the summer, or maybe even the year.

“We hope the population will not go up, but we are preparing for the worst case scenario,” he said.

Just not with the help of copepods.



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