Frank Chesniak questioned whether or not the woolly bear caterpillars he noticed in his woodpile Sunday had been lifeless.
‘‘The woolly bear caterpillar (or, extra exactly, the Isabella tiger moth) is a good instance of insect methods for chilly and has change into pretty well-known within the literature,’’ emailed Derek Rosenberger, an affiliate professor in Wheaton School’s Conservation and Ecological Well being Program, who labored with mountain pine beetles and researched chilly tolerance.
‘‘Most bugs in temperate areas will develop chilly tolerance to some extent by the autumn as cryoprotectants develop of their our bodies. Cryoprotectant compounds enable the bugs to decrease the purpose at which ice will kind of their our bodies, which is sweet! The mountain pine beetle as an example . . . may survive temperatures right down to -22 levels Fahrenheit!
‘‘Nevertheless, regardless of decreasing the freezing temperature of their physique fluids, some bugs nonetheless die previous to freezing, and a few can really survive their our bodies freezing! Bugs that survive freezing are referred to as freeze-tolerant bugs. The woolly bear falls into this particular class. Temperatures have to go beneath round 15 levels Fahrenheit for the caterpillar to freeze, however even then, after thawing, it may possibly survive. In our area, nonetheless, the caterpillar would possibly have to rely on this technique a number of occasions, which may be pricey to the insect, as a paper out of Brent Sinclair’s lab has proven, with every freezing occasion lowering its chance to outlive.’’
Right here is an prolonged clarification from Rosenberger:
So, what woolly bear caterpillars might do is hunt down a spot that is perhaps buffered towards temperature fluctuations. The subnivean surroundings beneath snow is a good place, because the temperature stays pretty constant. Different locations is perhaps below leaf litter or in wooden piles, which is the place your reader discovered their specimen ready out the winter.
With the ability to survive freezing, somewhat than decreasing your freezing level in order that freezing doesn’t happen, is a extremely neat however not so frequent overwintering technique, so this critter has gotten fairly a little bit of consideration within the insect chilly tolerance circles.
Rosenberger linked to this: The sub-lethal effects of repeated freezing in the woolly bear caterpillar Pyrrharctia isabella | Journal of Experimental Biology | The Company of Biologists
Wild issues
A number of readers have reported lifeless waterfowl from suspected avian flu and marvel what to do. Begin with this on the protocols from the Illinois Division of Pure Sources: dnr.illinois.gov/press-release.30768.html.
Stray forged
Bears followers are like largemouth bass with a number of previous hook marks.
