Yesterday, Judy Dluzen, one of Matthaei-Nichols' horticulturists, pointed out an interesting bunch of tiny caterpillars on one of the milkweeds between the greenhouses. We knew they weren't monarchs, and after a little research discovered them to be early instar milkweed tussock caterpillars. Toxins found in the milkweed called cardenolides provide the caterpillars a chemical defense against predators such as bats, birds, lizards, and other insects. Doesn't this late-instar tussock caterpillar pictured here looks a bit like the monarch caterpillar?
Here's a link to an article on the milkweed tussock moth. Look for them on your milkweed!
---Steve Parrish, Matthaei-Nichols