Gardening is always a challenge but look at all of the great things we learn each year, right!
If you have tomatoes, be on the lookout for the giant hornworm caterpillars on the plants. They can devour numerous leaves in a single day.
These giant caterpillars (both tobacco and tomato hornworm) are actually pretty cool because of their size. They are the larvae of sphinx moths and grow to around 4” long and about 1/2” in diameter, making them an impressive catch in the garden world.
They get their name hornworm from the horn-like appendage that sticks out from the end of their abdomen.
Despite their size, they are sometimes hard to find as their green color blends nicely into the foliage. I look for their telltale frass (bug droppings) on the ground around the tomato plants.
Their frass is about the size of bb bun pellets, black and barrel-shaped. I usually find this before I can find the pesky caterpillar.
The other telltale sign is significant amounts of missing leaves or even chunks taken out of the fruit. I once blamed a mouse for this until I found the caterpillars.
Once you find these insects the easiest thing is to handpick and squish. Make sure you have someone who is not squeamish do the squishing!
I asked Natheta Mercer, one of our Master Gardener volunteers, to pose for a photo of her foot stomping a small cabbage moth caterpillar and then asked her to do the follow-up squish so that I could get the photo to teach people this method. She about died, thought I have to admit, it was pretty smushy and gross.
If you find the caterpillar and it has white cottony-like tiny ovals lined on its back, leave it alone. This is actually a good thing!
The white cottony like things are actually pupal cases of a tiny parasitoid wasp. The adult wasp hunts for these caterpillars to lay her eggs and inserts them into the caterpillars.
As the eggs hatch and larvae develop, they eat the inside of the caterpillar leading to of course, death of the caterpillar. How cool is that?
The wasps then pupate outside of the body of the caterpillar and emerge as adults to continue their foraging.
In the integrated pest management (IPM) world, this is allowing a beneficial insect to take out the bad pest. By allowing them to finish their development on the back of the caterpillar, you encourage populations of the biological to continue to do their work.
Isn’t Mother Nature very cool?
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