Planes to spray for gypsy moths in western Wis.

Low-flying, single-engine planes are doing spraying for gypsy moths this week in western Wisconsin.

The invasive moth feeds on the leaves of oaks, maples, crabapple, birch and other species of trees and shrubs.

The planes apply pheromone flakes, which don’t kill the insects but disrupt mating.

The flakes — about the size of a grain of rice — trick adult male moths from finding females. Only the males fly and the females release a pheromone for the males to track.

The spraying does not affect organic certification. It’s not toxic to people, bees, animals, birds and plants.

The spraying will run from Thursday to Saturday in parts of La Crosse, Jackson, Clark, Eau Claire, Chippewa and Taylor counties, weather permitting.