Nature Notebook – Wasps hunting caterpillars

The sight of a wasp around plants frightens most people. A knowledgeable gardener, however, happily embraces the insect’s presence.

Both solitary and social wasps are extremely beneficial to gardens. The adults eat pollen and nectar and, in their search for food, pollinate plants. They are as proficient at this job as honeybees.

Wasp larvae eat insects and arthropods. The worm-like young cannot hunt for themselves so adults provide the food. Solitary wasps capture their prey with paralyzing venom. This ensures that the living victim food does not rot away before the larvae eat it.

Social wasps don’t sting their prey. They only use their venom for defense. Instead, they use their powerful cutting mandibles to cut caterpillars and beetle larvae into bite-sized pieces.

It is not a quick process. As I watched the paper wasp in the photo below, it appeared to be licking the caterpillar. I thought it might be getting honeydew off the caterpillar…similar to ants “milking” aphids for honeydew. After a few minutes, however, the wasp lifted its head with half of the caterpillar in its mouth.

The plant now had one less pest eating its leaves.