Saturday, May 28, 2011

silver-spotted tiger moth ~ 05/28/11 ~ at home

silver-spotted tiger moth caterpillar (or nameless arctiid moth) feeding on coast Douglas-fir
Lophocampa argentata (or L. sobrina) feeding on Pseudotsuga menziesii var. menziesii

posted 06/18/11 - I mainly want to show the color variation of these caterpillars that I'm attempting to raise - from bright white to tan side hairs. These three were munching away at young shoots of Douglas-fir. I collected a third caterpillar from the Highlands the day I took this picture on 05/28/11. Add in the two I found around home, I've had 5 total. They seem to prefer hanging out together; in fact, they'll follow each other along a plate's edge like a caterpillar conga line whenever I switch out food. Except for the Highlands Easter caterpillar, I don't know which individuals came from where.

One successfully pupated and has been tucked in its cocoon since 05/01/11, one died 05/21/11 from what appeared to be parasites, and another one died 06/10/11 from what looked to me like typical Btk poisoning - the body was deflated and limp, like a plant that hasn't been watered, with only the middle sets of prolegs keeping the body attached to the nylon top.

I moved the two remaining caterpillars to a clean container. They now occasionally feed on Monterey pine (Pinus radiata) even though I'm still providing a mix of clippings. They rest most of the time upside down from a new nylon top. Their poop has gotten inexplicably smaller. I'm starting to get concerned because they don't seem to be progressing in their development. I suspect they may need a snack of another plant in order to successfully pupate - this is totally wild speculation after reading about Queen butterflies needing to snack on non-host plants in order for their adult pheromones to be chemically complete. I'm starting to remember all too clearly why I once gave up rearing caterpillars. Click to read a past post about how and why I'm raising these caterpillars.

ps 06/25/11 - As I was changing out the tree clippings, one of the caterpillars had started making a cocoon with hairs from its body and silk. I hope I didn't disturb it too much.