Woolly bear caterpillar In earlier times, when most Americans were involved in agricultural pursuits, the nation s welfare was defined by the weather, and severe winters had severe consequences. Folks living close to nature observed how plants and animals seemed to prepare for winter. Weather folklore is rich with insect and spider motifs. Large numbers of spiders or crickets in the house foretell of cold winters. Bees prepare an unusually large store of honey before a severe winter.
Flies seeking shelter in early autumn are harbingers of frosty mornings and cold storms.
But our most famous six-legged weather prophets are woolly bear caterpillars, which are said to predict the severity of the coming winter by the relative widths of their black and brown bands. Each of its three thoracic and ten abdominal segments is ringed by tufts of long, stiff, barbed spines or setae that arise from closely spaced tubercles on the black integument. These setae no doubt offer enemies an uncomfortable mouthful. Early farmers observed that chickens would scrutinize the caterpillars, but would not devour them. In mature caterpillars, the segments of the front and rear ends bear black setae, and typically four to six middle segments have reddish-brown setae.