SMITHFIELD, R.I. (WLNE) - For the first time in 23 years, the state of Rhode Island is conducting aerial mosquito spraying.

Crews with the Department of Environmental Management were out early Thursday morning, loading a helicopter full of larvicide pellets, which are different than traditional spray pesticides like those being used in Massachusetts.

"So these pellets go down into the swampy areas and into the water and dissolve," explained Mike Healey with the DEM.

"Then the larvae — the immature mosquitoes that hatch from eggs will consume that and will die. So the point of this operation is to kill those larvae before they become adult biting mosquitoes."

The pellets are non–toxic to humans, animals, and even other pollinating insects.

So the spraying can be conducted in broad daylight.

"We're going to be dispersing a thousand acres worth, and that's going out at a rate of 7.5 pounds per acre," said helicopter pilot, Ray Feeley. 

Three different areas in the state are being sprayed Thursday, including:

-The valley marsh area surrounding Lincoln, Cumberland, and Central Falls

-The Chapman Swamp in Westerly

-The south branch of the Pawtuxet river in west Warwick

"So this year, for whatever reason every three or four years, there is a very active mosquito year and a heightened risk for EEE and West Nile Virus," said Healey. 

So far this year, there have been four cases of EEE detected in Rhode Island, including in Central Falls and Westerly, and one human case in West Warwick.

There has also been one detection of West Nile Virus in Tiverton.

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