I often consider caterpillars as slightly delicate creatures and marvel why woolly bears don’t spend winter in a extra sturdy stage like an egg or pupa, as do many different moths and butterflies. Even in Maryland polar vortices typically go to and drop temperatures beneath zero. An enchanting research by Jack Layne and his colleagues revealed that woolly bear caterpillars survive winter’s chilly by a course of known as supercooling. As temperatures drop in autumn and early winter, woolly bears and plenty of different species of bugs produce cryoprotectants, antifreeze-like compounds together with glycerol and sorbitol, that forestall the formation of deadly ice crystals of their our bodies. This brew of Mom Nature’s antifreeze permits caterpillars to outlive even when ambient temperatures dip properly beneath freezing. The power to shrug off chilly permits the partially grown woolly bear caterpillar to overwinter as a larva, and with the return of heat temperatures in spring and arrival of contemporary leaves, the caterpillars resume feeding for some time earlier than spinning a cocoon and finishing the transformation to an grownup moth.
Think about my delight when on a latest journey to the sector, I found a banded woolly bear caterpillar with nearly no black bands on its physique save for a number of darkish segments close to the top. What with wildly inflating gasoline costs and my historic furnace gulping gallons of gasoline oil, the prospect of decrease oil payments loomed massive. These hopes had been totally dashed per week later after I noticed a banded woolly bear with however a number of orange coloured segments within the center and vast black bands at head and tail sanctioning the Farmer’s Almanac forecast of extreme climate forward. Has discord so rampant on the planet of people unfold to the realm of woolly bears as properly? Let’s hope not. Maybe these seemingly disparate meteorological predictions are reconciled like this: “Woolly bears are predicting a comparatively delicate winter with intermittent intervals of extreme chilly.” Intelligent meteorologists are these woolly bears.
Bug of the Week thanks Sheri, Finn, and Iggy for uplifting this episode and Karin Burghardt for offering pictures and figuring out featured caterpillars. David Wagner’s outstanding guide, “Caterpillars of Jap North America”, was used to arrange this story, as was the attention-grabbing article “Chilly Hardiness of the Woolly Bear Caterpillar (Pyrrharctia isabella Lepidoptera: Arctiidae)” by Jack R. Layne, Jr., Christine L. Edgar, and Rebecca E. Medwith.