Wasp-eating moth fills rare niche
We had lured a sootywinged chalcoela, or Chalcoela iphitalis.
Someone mentioned that it is a parasite that kills paper wasps.
“What?” I exclaimed. “You’ve got to be kidding!”
Nearly everyone knows paper wasps, in the genus
They construct manychambered, papery nests that hang from slender stems under the eaves of buildings and other structures. The adult wasps fiercely protect their nests and a female’s sting packs a punch.
Sure enough, sootywinged chalcoela caterpillars consume the larvae of various paper wasps. This is rare. The vast majority of caterpillars, the larvae of moths and butterflies, are strictly vegan.
Soon after my initiation to this bizarre moth, an acquaintance showed me a photo of a moth that mystified her. It turned out to be a sooty-winged chalcoela, resting on the side of her house only inches from an active paper-wasp nest.
Figuring that the moth had raided the wasp’s lair, we hatched plans to inspect the nest once winter set in and the wasps were gone. On the frosty night of Dec. 23, we removed the wasp nest from the eaves and took it inside for inspection.
It didn’t take long to find the tiny moth caterpillars. The nest was infested with a dozen or more.
Each of the cells within a paper wasp nest contains a wasp larva, or grub. The female chalcoela moth flies to the nest under cover of darkness, when the wasps are inactive, and lays eggs on the structure. Caterpillars soon hatch, invade the cells and consume the wasp grubs.
By the onset of winter, the caterpillars are ensconced within dense silken cocoons woven within the cells, or on the back of the wasp nest. Come summer, the adult moths will emerge and begin the cycle anew.
As adult paper wasps often hunt and feed on moth caterpillars, this is a particularly apropos form of revenge.