UMass Extension Landscape Message April 9, 2010
"Winter Moth - The caterpillars began hatching in Plymouth County late last week, most likely on April 2, 2010. These tiny caterpillars can now be found sitting on (and feeding on) expanding buds of Norway maple, blueberry, apple, and other deciduous hosts. For those plants where the buds are starting to swell but not yet open, winter moth may be feeding within the buds and causing damage. Controls in this case are not possible. For exposed caterpillars on expanding buds, a spray application of a product that contains spinosad should be very effective. Also, Bacillus thuringiensis (Kurstaki), pyrethroids, and other chemical insecticide families work well."