Wednesday, August 17, 2011
Garden Update and Nature Study: Tomato Hornworms
Wow these things are creepy. I literally screamed out loud and ran from the garden when I spied them. I was watering the tomato plants and looking for any tomatoes that were eaten or ripening and when I stood up I was eye to eye with this guy and his friend.
I ran into the house for dear hubby who helped with the removal. He pulled off the leaves they were on and then squished them.
Being the homeschoolers that we are, we decided this would make a great little nature study. So here is what we learned. First of all - not worms as the name would imply. They are actually the caterpillar of the sphinx moth. The hornwom grows to be about 3-4 inches in length.
The moths overwinter in the soil as dark brown pupae, then emerge and mate in late spring.
They lay their eggs, which are round and greenish-white, on the undersides of leaves. The
eggs hatch in four to five days, and the hornworm emerges. It spends the next four weeks
growing to full size, after which it will make its way into the soil to pupate.
Next we wondered what are all those yucky white things on it? Well turns out these are the larvae of the Braconid wasp. And according to several sources I found on the internet, we should have left these hornworms alone because their days were numbered anyway. The Braconid wasps are harmless to humans and beneficial to gardens. They lay their eggs inside hornworms and a few different species of beetle, then the larvae push their way out and when the fully grown wasp emerges from those rice looking cocoons, the host, in this case the hornworm, dies. Then you have no more hornworm plus a bunch of new Braconid wasps to lay eggs in any new hornworms that may make their appearance.
After all the difficulty I've had with my tomatoes this year I needed some vengeance. Those little puppies were squished and I felt good about it! Maybe we'll finally get some tomatoes to eat.