It was well after midnight on a hot and sticky weeknight in Washington Heights in Upper Manhattan when the hunt got underway.

A police car rolled slowly through the empty neighborhood in the predawn hours, its lights casting shadows on the buildings as a voice over a loudspeaker blared a warning to clear the streets.

Following behind, at six miles per hour, was a white pickup truck carrying men in protective clothing and equipped with a machine intended to cast off a cloud of poison targeting the prey: mosquitoes.

The droplets would awaken any insects in the area, cause them to take flight and then kill them.

The spraying is called adulticide — as opposed to larvicide, or killing insects before they hatch — and it was the first time that such a truck had ever rolled through the neighborhood.