July 17, 2012

Big Green Eating Machine

Plucked any of these bad boys off your tomato plants yet this summer?

Tomato hornworm

This is a tomato hornworm, a fat caterpillar that can be thicker than a Sharpie and up to four inches long, and that favors plants in the nightshade family, especially tomatoes. The hornworms we get in the garden this time of year are so big and colorful that they even intimidate the chickens, who squawk loudly, back up and refuse to eat them when they're tossed into the coop. I've tried several times. I kind of expected the chickens to be like kids, who will eventually try a food if you put it in front of them enough times, but no, they want nothing to do with these things. Must be that "horn" on the rear end.

Tomato hornworm

If you notice that the tender tips of new growth on your tomato plants are missing, a tomato hornworm is the likely culprit. Here's what the damage to one of my plants looked like this morning:

Hornworm damage on a cherry tomato plant

The tricky thing is that tomato hornworms are incredibly hard to spot on the branches of a tomato plant. They are exactly the same color, and are a similar thickness to the stems, and their slightly fuzzy bodies even mimic the fuzzy roots that cover tomato stalks. They can be almost impossible to see even if you're looking right at them. We have resorted to paying the kids 50 cents for each caterpillar they find, but sometimes even the kids get frustrated and give up after looking for just five minutes. Maybe we'll have to up the pay.

If you can't find the actual caterpillar, the other way to know you've got tomato hornworms on your plants is to look for their poop. A telltale sign of the caterpillars are the little piles of round, black excrement you'll find on the leaves. The caterpillar that left the goodies in the picture below must be relatively small; a big caterpillar leaves surprisingly big poop!

Evidence of tomato hornworms

If you don't find and eliminate the caterpillars, they eventually drop off the plants, burrow into the soil, and transform into a pupae, which emerges the following spring as a large, brown moth. The moth lays its eggs on your new tomato plants and the cycle starts all over again. And there you have yet another reason why I plant so many tomatoes! If the hornworms diminish the crop a bit, no big deal.

Like other garden pests, tomato hornworms are actually kind of pretty and I wouldn't mind having them around if it weren't for the fact that they're destroying my food source.

So, have you seen any of these in your garden yet this season? Do you have a laissez faire attitude about the caterpillars, or do you take quick action to find and get rid of them?

1 comment:

  1. Quick action - with apologies to the caterpillar.