Gigantic green caterpillar is allowed to crawl on man's arm

This gigantic green caterpillar was found wandering over a stump at a cottage in Parry Sound, Ontario. It was as big as a small sausage and the mandibles looked strong enough to cut through a small sapling.Show more

These caterpillars metamorphose into the Polyphemus moth, one of the largest moths in North America.

These caterpillars feed voraciously for two months before making a cocoon and pupating. They eat the leaves of birch, oak, hickory, walnut, and fruit trees and they are able to strip the leaves off the entire branch in one day. Due to their relatively small numbers, Polyphemus moth caterpillars do not pose a threat to trees or forest. The caterpillars hatch into huge, brown moths that have non functional mouths and no digestive system. They have a very short life span, living only 7-10 days. During this time as adults, they do not eat. They reproduce as quickly as possible, laying hundreds of eggs, continuing the cycle.

The most striking feature of the Polyphemus moth is the large spots on the wings that resemble large eyes, a self defense against birds and other predators that will mistake the moth for part of a larger creature. Females will mate once and then spend the rest of their brief lives laying eggs. The male may mate several times. The female will emit pheromones which the male can detect from more than a mile away to help him find her. From the time that a Polyphemus moth caterpillar emerges until it dies, it will consume 86,000 times its initial weight on vegetation as it grows rapidly. As adults, the moths have a wingspan of 4-6 inches (up to 15cm). They are strikingly beautiful. Although they are not uncommon, they are rare to see due to their short lifespan and nocturnal habits.