The Isabella tiger moth (Pyrrharctia Isabella) aka “woollybear” is native to North America and can be found throughout the US into Southern Canada. They have two generations per year and spend the winter frozen solid as caterpillars. They produce a substance called cryoprotectant that prevents the inside of their cells from freezing, allowing them to survive the winter and thaw out in the spring. They have a very generalist diet and feed on a wide variety of herbaceous plants and tree foliage bu

Seven minutes of a woollybear caterpillar hatching from its egg! Who watched the whole thing? Do it! I watched this egg for a loooooong time to capture the moment. The Banded Woolly Bear or Isabella Tiger Moth, Pyrrharctia isabella, overwinters as a final instar caterpillar, feeds for a time in the spring and then builds a cocoon and pupates. At The Caterpillar Lab, we accelerated a few woolly bears that we found nearby and the resulting moths already eclosed, mated and laid eggs. Now, here we a

The woolly bear caterpillar (the larval stage of the Isabella tiger moth) is often said to predict the severity of the coming winter based on the width of its brown band: • Wide brown band → A milder winter ahead. • Narrow brown band (more black at the ends) → A harsher, colder winter. This belief comes from American folklore and has been around since the 1800s. In reality, scientists have found that the band size is more related to the caterpillar’s age, growth stage, and past weather condition