My loyal and brainy readers quickly identified the caterpillars I saw recently. It's bad news: they're gypsy moth caterpillars, a "regulated pest" in this part of the world. They were first discovered in Canada in 1924 and have been spreading ever since. The larvae prefer oak and aspen trees but will eat many other kinds as well. Mississauga mounted an aerial spraying campaign last year to deal with an infestation, and a few areas in Etobicoke were sprayed this spring.

A major infestation can defoliate a significant area, and the hairs and droppings (frass) of the larvae can cause rashes and respiratory problems in people. I've seen the caterpillars in a few places now, but the biggest gathering was right within our own stewardship equipment box. Talk about rubbing our noses in it! I'm afraid the ones pictured here met with a tragic end shortly after the photo was taken. Hey, they were filling our box with frass.

("Frass" makes a good swear word, almost as good as "vetch." Try it.)

These are big, meaty caterpillars, and small mammals and some birds like to eat them. Other dangers for them include viruses, fungi, and newly enlightened stewards.

My question now is, how did I not already know about these things? Have I just not been paying attention? I spent ages poring over caterpillar images online, trying to make an ID without success. (I did find them at bugguide.net after I knew what to search for.) Shouldn't there be WANTED posters on every corner to educate people about gypsy moths? It's the same story with invasive plants like dog-strangling vine and garlic mustard: after a session of removing them from Beechwood I walk back through my neighbourhood and see them growing in flower gardens. People just have no idea what they are, so they don't get rid of them. How do we spread the word?