Sorry my previous notes and photos disappeared. I have a tussock caterpillar colony on my milkweed plants. Should I leave them or remove them? This is the first year for my milkweed plants. I was hoping for monarch caterpillars. What is your opinion about what I should do about the tussock moths caterpillars? Thank you,
The photos came through this time.
Baltimore County Maryland
These milkweed tussock caterpillars are very gregarious, aren't they? Since you are hoping to help monarchs by providing food for the monarch caterpillars, you'll be glad to know that it has been reported monarch caterpillars generally feed on the young foliage of milkweed, whereas the tussock moth caterpillar eat the later, older foliage. So, they is not a problem in that respect.
However, if you're concerned that they are devouring the entire plant to the point that the plant would be killed, you can easily clip off the whole horde or knock them off into a bucket of soapy water to drown them. They mature into a muddy gray moth.