Fall Webworm, Hyphantria Cunea

Day 351: Every autumn, I hear people talking about seeing the "tent caterpillars" whose webs adorn vast numbers of fruit and other deciduous trees. No, despite the fact that the webs are similar, these caterpillars are not the same pests we see in the spring. They are not Malacosoma fragilis (Western Tent Caterpillar, orange) or M. disstria (Forest Tent Caterpillar, blue). They are Hyphantria cunea, aka Fall Webworm, a distinctly different biological family (Erebidae vs. Lasiocampidae). Their webs are more openly structured than those of tent caterpillars, making it easier to see the critters crawling around inside. Despite the devastation these insects wreak, devouring leaves and leaving branches bare, arborists say that they are largely an aesthetic pest and do not damage trees significantly since the leaves this autumn nuisance consumes would fall naturally in just a few weeks. The moth of this species is bright white with a few black flecks on the wings.