Spurge Spanworm Caterpillar (and Predator)

This spurge spanworm caterpillar (Oxydia vesulia) is expertly camouflaged as a stick, but that did not do it much good against the nest of tiny scorpions it happened to wander over. I saw the caterpillar on the wood and took a photo of it — and only saw the suspicious, grasping claws after enlarging the photo.

Alas, the caterpillar was already very, very dead. There were at least four scorpions in that crevice under it, working to pull it down into the hole with them. I tried to roll the caterpillar over with a leaf; the scorpions exerted enough force that I could not budge it.

Spurge spanworm moths are in the family Geometridae, and their larvae resemble sticks in the most amazing ways, including behavior: the caterpillars will stand themselves up, using those big, heavy legs in the back, and tuck in their heads and forelegs to look more like a broken-off branch.

I couldn’t possibly identify the (probably juvenile) scorpions just from their pincers, but there are scorpions native to Florida. The most common is the Hentz striped scorpion, Centruroides hentzi, which gets to be about an inch and a half long as an adult, and that might be a good guess for these. Or, possibly these are pseudoscorpions, tiny things that look like scorpions but lack the stinging tails of their larger cousins. I didn’t get a look at their back end so I could not say.

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