k8thegr8 Curator

Joined: Aug 02, 2016 Last Active: Jun 20, 2021 iNaturalist

Caterpillars! So much to know, so little time. I'm still learning, but trying to help with ID's when I do recognize a caterpillar. Sadly, I can't identify adults, chrysalis/cocoons, or frass (poops). I'm getting acquainted with North American caterpillars, but have a hard time with critters in other places (for now).

Caterpillar photography tips! The little things are very uncooperative. They roll up or thrash or hide their heads when we're trying to get their pictures! When possible, try to get a picture of the back of the caterpillar (from the top), a side picture, and one of the head (head capsule). I know they are often hard or impossible to reach, but the more information in the picture, the better. Host plant information can also be used to tell the related species apart. If a separate observation is made for the hostplant, that can be referenced or linked in the caterpillar observation.

Caterpillar trivia! The smooth ones are safe to handle in general, caterpillars don't bite! If it has spikes, hair, fuzz, or a terrible attitude it's better to wait before handling. Some caterpillars thrash around, roll up into balls, spit up green stuff, or even hiss/squeak when bothered. Some groups of moths can only be told apart by dissection, even as adults. One group like this is the Pug moths, genus Eupithecia. There are 160 species in that group in North America!

Caterpillar resources!

For the US and Canada: https://bugguide.net/node/view/57/bgimage Bugguide
For Central Americas: http://janzen.sas.upenn.edu/caterpillars/database.lasso

I would love to know if there is an online guide for the caterpillars of Mexico. Email me if you know of one!

If I've moved your Orgyia species of tussock moth away from the genus level, here is why:

The experts say it's probably impossible to ID this caterpillar to species level from a picture because there’s so much inter- and intra-species variability.

What's That Bug?
"There are several species of Tussock Moths in the genus Orgyia that are found in California... it may be impossible to determine the exact species with an image since all members of the genus have very similar looking caterpillars and there is also much variation within the species."

Bug Guide
Taxonomy: https://bugguide.net/node/view/335/tree
Species in CA:

O. magna (no pictures in Bug Guide)
O. pseudotsugata (Douglas Fir Tussock) https://bugguide.net/node/view/29616/bgimage
O. vetusta (Western Tussock Moth) https://bugguide.net/node/view/18317/bgimage

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