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Posts tagged “Arctiidae

Woolly Bears Wandering

3-15-16 woolly bear 119 Woolly bears (larvae of the Isabella tiger moth) are on the march again- several weeks before I have seen them in past years, no doubt due to the warm weather we’ve experienced lately. They are one of the few moths or butterflies that overwinter as caterpillars. In the fall, often around the time of the first frost in the Northeast, woolly bears are often seen crossing roads as they wander frenetically prior to hibernation. At this time their body produces a chemical called a cryoprotectant that acts like an anti-freeze which protects living tissue against damage from freezing and thawing. They remain curled up in a protected spot, such as in leaf litter or under loose bark, nearly frozen solid all winter. When spring arrives and the temperature reaches the high 40’s and 50’s they become active again, feed for a few days, and then pupate inside a cocoon made with their own bristles. Adult Isabella tiger moths emerge in about a month, anywhere between April and June, mate, and lay eggs. Within two weeks the eggs hatch. In New England a second generation of woolly bears will be produced and these are the larvae that overwinter. (In even colder regions, such as the Arctic, there isn’t enough time for woolly bear caterpillars to consume enough food to achieve adulthood within a year, so they spend several summers feeding, hibernating each winter, for up to 14 years.)

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Clymene Moths Active

8-4-14 Clymene moth 140The Clymene Moth, Haploa clymene, is noted for the striking upside-down cross pattern on its forewings. Because of this design, some people refer to it as the “Crusader Moth.” A member of the Tiger Moth family (as is the Woolly Bear/Isabella Tiger Moth), the Clymene Moth can be seen flying day or night. Typically they inhabit deciduous forests and fields adjacent to them where the black, bristly larvae feed on a wide variety of plants, including willows, oaks, and members of the Aster family. In contrast to its white forewings, the Clymene Moth’s hind pair of wings is bright yellow. Its long proboscis allows it to reach deep inside the nectar-bearing hoods of Common Milkweed.

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Woolly Bears on the Move

Although it’s fun to try to predict the severity of the coming winter by the amount of brown on a woolly bear caterpillar (the more brown = the milder the coming winter, according to folklore), the coloration of any given woolly bear caterpillar has more to do with its diet and age than the coming weather.  The more a Woolly Bear eats, the more frequently it molts, and each time it molts a portion of the black hairs (setae) is replaced by brown ones.  A Woolly Bear can molt up to six times — the best fed and oldest woolly bears, which have molted the most number of times, have the widest brown bands. (After overwintering as caterpillars, Woolly Bears pupate and emerge as small, brown moths called Isabella Tiger Moths, Pyrrharctia isabella.)


Hickory Tussock Moth

 

Most tussock moths, such as this Hickory Tussock Moth (Lophocampa caryae), are densely covered with hair-like structures called setae that bear microscopic barbs.  Many people are sensitive to these setae and get an itchy rash if they handle a Hickory Tussock Moth.   Even touching the cocoon of a tussock moth can cause irritation, as the setae are woven into it.  Many tussock moths display warning coloration with their black, white, red, orange or yellow setae.  What looks like two Hickory Tussock Moth larvae in the photograph is actually one adult caterpillar (left) and its shed skin (right).   You can find these larvae feeding on hickory, walnut, ash, oak and many other trees in the woods right now.  After spending the winter pupating in a cocoon in the leaf litter, a small spotted, tan moth emerges.