Gypsy moths eat the leaves of hardwood trees. They came over from Europe and have defoliated many forests on the east coast and are moving to the midwest. There is also the Asian Gypsy Moth that came over from Asia and is now in the pacific northwest. If the trees are healthy, they can take one or two defoliations (especially the oaks) and survive. The populations go sky high in the first year or two of infestation, but then the predators catch up and they become a background pest. When you have a gypsy moth invasion--it is not the moths that are the problem--it is the catepillars that are EVERYWHERE--on your walls, your roof, the road, the sidewalk. But unless VERY desparate, they will not eat the needles of conifers.
