One of us missed the memo. Fall webworm caterpillars, Hyphantria cunea DP218-2013 Posted August 6; processed August 5 This species is supposed to hatch, or whatever you call it to go from egg to larval stage, in 'late summer or early fall', when leaf growth and food production for the plants is mostly over. Either I missed the memo about it being late summer already, or the caterpillars missed the memo about it still being mid-summer. For a couple of other views of these hairy things, see here: Huron River, below the Kent Lake Dam. Michigan, August 1, 2013 Update: Nelli (Donna) asked if the caterpillar turns into a butterfly. After its pupa stage, which overwinters, it becomes a rather nondescript looking moth. Here's a link to Wikipedia's article: - arctangent