It sure is a shock to discover how much these caterpillars can munch overnight! Unless I'm really overrun with them, however, I've taken to moving hornwoms from my tomatoes onto alternative host plants. The moths they become are just too lovely to resist!
I have always loved tomatoes and they have always grown well so I don't fuss over them at all--except to pick these caterpillars off. I usually destroy them as that is just how my Dad always did. But recently as I was plucking some off my plants I wondered if I could just relocate them? What will they live on and do less damage?
Also I planted my tomatoes in a bed that held zinnias last year. Of course many zinnias came up and I couldn't bear to pull them out so my tomatoes are surrounded with pink flowers. Maybe this is what is attracting the moths in the first place? I have had more hormworms this year than ever!
A security light at night is a draw for the moths and the year I had them on Datura was the year I had about 6 under a light to enjoy the white blooms at night. But the scent of a host plant will draw them too.
For the past few years in my garden I've found only two hornworms and both were prickly with wasp larva, so I let them be. Haven't spotted any hornworms this year.
I never kill wasps--even when they build nests near the back door, I only move the nests (early in the morning when it is cool--and I take care to be very covered up.) Wasps pollinate figs--and I love my figs.