Subject: Black Bristly Caterpillars
Geographic location of the bug: San Diego, California
Time: 03:05 PM EDT
Your letter to the bugman: Dear Bugman, I have been finding these black bristly caterpillars every spring for 3 years in my backyard. They don’t have red or Orange bands so they aren’t Leopard Moth Caterpillars (Which is what ice been calling them). They have pale red/Orange bumps under they’re bristles. I have lots if questions so please write back asap!
How you want your letter signed: Savannah D.
This is the caterpillar of a Tiger Moth in the subfamily Arctiinae, the group that contains the Leopard Moth, though that is an eastern species. Considering your location, we suspect this is the caterpillar of a Painted Tiger Moth, Arachnis picta, a species that is quite numerous at our Mount Washington, Los Angeles office. Alas, our go-to site for identifications, BugGuide, has no images of Painted Tiger Moth caterpillars except newly hatched individuals, however, BugGuide does provide this description: “Larva – covered in dense black and cinnamon-colored bristles.” The adult Painted Tiger Moth is a lovely insect that is frequently attracted to porch lights.