not but a day or two after posting about the insects i’ve encountered in the garden, i found a nice crop of tomato horn worms. this is a nice big healthy one. if you have not encountered one of these, it can be a bit of a shock, they are huge, seriously the size of my index finger (though my hands are not all that big). with their large size and scary looking horn they can be a bit intimidating. but their bark is worse than their bit, as they can’t sting, and they to like to puff themselves up when disturbed and even thrash about. they can be tough to spot because of they green color and markings, i usually see the damaged leaves and giant green turds they deposit before I see the maker.
they can do epic amounts of damage, stripping large numbers of leaves overnight. it’s rare that their numbers are so great that they kill the plants, but they certainly can set them back. in controlled environments, such as hoop houses, i have seen their numbers get so high as to warrant a spraying of dipel. most of the time i hand pick them, but sometimes i let nature take it’s course. often you will see horn worms with these white cocoons growing out of their backs. they have been parasitized by a type of braconid wasp. not the sort of wasp you are thinking of, we rarely see these as they are so small – in fact if you look closely you can see one on top of one of the cocoons in the middle of the photo. the adult wasp lays eggs under the tomato horn worm’s skin and then the larva eat the horn worm alive, pupating and hatching out of the cocoons formed on the surface. any time i see the cocoons on a horn worm, i leave it figuring it means more wasps to take care of horn worms i haven’t discovered, cruel perhaps, but then no one ever said nature didn’t have a cruel streak.