Columbia Silkmoth caterpillar

Someone spotted this huge, green caterpillar in Weaselhead this morning. I love the tiny black spots on the few yellow knobs at the head end (i.e. top of the photo)!

"The Columbia Silkmoth is one of the largest moths in Alberta, reaching wingspans of 10 cm. The caterpillar can achieve lengths of 5 to 6 cm. Because the moth is active at night it is seldom seen. However, when seen it generates a lot of curiosity because of its size. The size of both the moth and caterpillar eliminates almost all other species. The green colour and rows of fleshy knobs separate the caterpillar from similar species. Caterpillars first appear by about mid-July and mature by early to mid-August. The cocoons are formed from leaves and silk, and are located in protected areas. They over-winter in this stage and the adults emerge the following June. Caterpillars feed on a variety of plants, including rose, birch, maple, ash, oak and pine. For this reason they are found in wooded or shrubby areas. This species is seldom found in numbers sufficient to be considered a pest species, and its beauty far outweighs its destructiveness." Taken, with thanks, from The Royal Alberta Museum website.