DETROIT – It’s no big surprise to see a caterpillar roaming around in Michigan in the summer -- but this particular one is not to be messed with, even though it looks cool.
The White-Marked Tussock Moth Caterpillar (Orgyialeucostigma) looks like something out of Alice in Wonderland. It is common in North America in summer months, mostly in the south and eastern states, although they have expanded north for several years. They are considered widespread in Michigan.
They’re hard to miss. They have long brown hairs, a yellow-ish body, long antenna-like hairs on front and back and multiple white poofs on its back. (More scientifically from MSU: Full grown larvae have a bright red head with a yellowish body, a pair of upright pencil tufts of black hairs on the prothorax, and four white to yellowish brushlike tufts of hairs on the top of the body toward the head.)
Some information on the species here from MSU Extension:
This insect has two generations in southern Michigan with peaks of larvae on bushes in June and again in August, and peaks of moth activity in late June and late August. The whitemarked tussock moth overwinters in the egg stage within a large mass of eggs nestled in a hard foam that is wrapped inside a dry leaf. These are usually found on stems and are visible during pruning.
The eggs hatch during bloom and larvae stay close to the egg mass at first, dispersing in the plant canopy after a few days. Larvae feed in the shady parts of the canopy until full grown in late June/early July. At this point, they pupate on the bush and emerge in July as adult moths. The female moth is flightless and stays on the leaf she pupated in, mating and laying eggs in this same position.
The insect can be damaging to crops and woodlands, but luckily, there are enough predators to keep the species in check.
Why you shouldn’t touch it
It’s not going to kill you, so don’t worry too much. But it could give you a bad rash.
Like other tussock moths, white-marked tussock moth caterpillars have urticating hairs (stinging hairs). The hairs are not attached to venom glands like the hairs and bristles on more dangerous caterpillars, but they can puncture the skin causing hives and skin rashes on individuals who are highly sensitive to the irritation.