Gypsy moth caterpillars are actively chewing foliage in orchards (where they occur) as can be seen here at the UMass Orchard in Belchertown. Do not be too complacent about gypsy moth, particularly young apple trees/new plantings. (They don't seem to bother stone fruit.) B.t. (Dipel, etc.) can be used to (eventually) control them, but must be used NOW when they are small, and it will take a while to work. Almost any petal fall insecticide (carbaryl, Imidan, etc.) will give quick knock-down and is highly recommended where they are doing a lot of chewing! For more information on gypsy moth, see the UMass Extension Landscape Message dated May 18, 2018. (Click on the Insects link.)