I don’t often see worms in the garden. The birds do a good job of keeping them in check. A few horn worms can strip an entire tomato to bare stems in a matter of days. They look ferocious with the spike on their tail but they are not poisonous. The 3.5 inch long horn worm below may have escaped the intestinal tract of a Robin but the Brachonid wasps found him.
The tiny beneficial wasp lays her eggs just under the skin of the worm. The eggs hatch and the wasp larvae eat the worm from the inside out. To make it worse (if that’s possible) the larvae nearly paralyze the host worm, which stops eating, while they mature. It is literally eaten alive.
To complete the life-cycle the larvae emerge to pupate. The cotton balls on the worm are the cocoon of the emerged larvae. Adults hatched a few days after this picture was taken.