By Liz Olson, Editorial Assistant

As I was puttering around my vegetable patch yesterday morning before work I noticed a large caterpillar on one of my heirloom tomato plants (‘Better Boy’). I had never seen one as big on a plant or with white on it, so I took a couple pictures. After asking my co-worker Nan about it and searching online a bit I found out that it is a hornworm caterpillar being attacked by braconid wasps.

Braconid wasps naturally control hornworm caterpillars. Female wasps inject eggs into the caterpillar’s body. The larvae that hatch from the eggs feed inside the caterpillar until they mature and eat their way out through the caterpillar’s skin. The caterpillars would otherwise eat the tomatoes.

It is a good idea to leave caterpillars with cocoons alone so the wasps can emerge to attack more hornworms. I did not know this when I saw it and killed it, but I’m glad to know for the next time.

What’s that Bug? Is an online source to help identify caterpillars.

Wednesday, August 22, 2007 9:39:46 PM (GMT Daylight Time, UTC+01:00)    Comments [2]