braconid wasp

I believe the white things are the cocoons that the wasps hatch out of. The eggs are microscopic and laid on the caterpillars back, the eggs hatch and the larvae (technically a maggot) burrow inside the caterpillar and float around absorbing nutrients from the body tissues. When the magic time comes all the maggots dig their way out through the skin and make the cocoons we can see.

Some county fairs have horn worm competitions where gardeners bring the biggest worms they can find. Most people don't know that the really big guys are infected with the wasp larvae. The wasp babies pump out chemicals that keep the caterpillar from developing into a pupae and then a moth. It is doomed the minute the wasp eggs hatch. It will live a much longer life as a walking cafeteria for the wasp babies and thereby get bigger and bigger all summer.

It doesn't matter where you put the "rescued" worm. The wasps will find the tomato patch and future hosts.

Good, because the slightly shrivelled hornworm with cocoons went on the mulch pile today.