You probably know this already, but if you find a parasitized hornworm, leave it. It won’t be munching on your tomato plants & the wasps that hatch will be hornworm hunters.
From link:
Rather than killing a hornworm outright, a female parasitoid wasp injects it with eggs and flies away, leaving her brood to hatch inside the live host. The eggs soon release little wasp larvae, which feed on the hornworm until they’re ready to pupate.
The larvae form cocoons outside the host’s body, and these white projections are easily visible to us. The hornworm is still alive at this point, and may continue walking around, but it has stopped eating. In fact, if you see a hornworm in this predicament, the best way to protect your garden is to just leave it alone.
“If such projections are observed, the hornworms should be left in the garden to allow the adult wasps to emerge,” UMES explains in a fact sheet on hornworms in home gardens. “These wasps kill the hornworms when they emerge from the cocoons and will seek out other hornworms to parasitize.”
https://www.treehugger.com/how-baby-wasps-can-save-your-tomatoes-from-hornworm-caterpillars-4868727
Mine were clean and green but good to know they have parasitic enemies and to look for white spots.
Yes, I’ve seen those wasp larvae on hornworms, but not for several years, for some reason.
When I was a kid, I felt sorry for the hornworm so afflicted.
Not so much, later on...