I used to get up early every summer morning to check my tomato plants for tell-tale signs of these tiny green eating machines. In those days, I bought in to all of the hype about how terrible Manduca sexta were, one of several in the moth family.
There are more than 1,200 species of these moths worldwide. Roughly 125 species can be seen regularly in North America. According to University of Missouri Extension, they are also called "hawk," "sphinx" and "hummingbird" moths. When in caterpillar stage, they are called hornworms.
For several weeks mid-summer, hornworm caterpillars consume large amounts of plant leaves including tomato, peppers, potatoes and sometimes eggplant, on their way to adulthood.
There are two hornworms often mistaken for each other. Tomato hornworms have eight V-shaped marks on each side of their body and a straight black horn on the rear. They are similar in appearance to tobacco hornworms, which have 7 diagonal white lines with a curved red horn. Both have a line of false eyes along their sides.
Once hornworm caterpillars reach around 4 inches, they drop into soil and hibernate in a pupa stage before turning into moths a few weeks later.
Hornworms are strong flyers, often visible daytime hovering in front of flowers to feed on flower nectar. When I first saw one, I thought it was a baby hummingbird. After taking several pictures, I noticed the lovely little "bird" had six legs instead of two.
I started to second-guess my habit of picking off caterpillars the summer I found a potted orange tree on my deck covered in what, at first, looked like bird poop. Once I had my glasses on, I saw those little brown and white mounds were actually Swallowtail butterfly caterpillars – dozens and dozens of them – eating the leaves.
Moths are butterfly’s night cousins. Like butterflies and bees, they are also pollinators helping to maintain, and expand, flower populations.
According to the University of Florida Entomology Department, wasp houses can be added to product fields to help keep hornworm populations in check. Wasps, also important pollinators, lay eggs on caterpillars and larvae basically eat the hornworms as larvae evolves.
I can understand how someone could get distraught over prized tomatoes loosing all of their leaves to ravenous caterpillars that can grow up to 4 inches long. For the record, my tomato plants quickly recovered from their temporary defoliation. I did loose a few green tomatoes but I picked those off so they didn't stress the plants.
As more of their native habitat disappears, caterpillars like tobacco hornworms are going to turn to our handy tomato plants to survive. Now I plant extra tomato plants to make sure these caterpillars have enough to eat, and I look forward to seeing them flying among my flowers.
Page 2 of 2 - And in case you were wondering, I still seem to have enough tomato
plants, and tomatoes, to go around.
Charlotte Ekker Wiggins is a certified gardener sharing gardening tips in a changing climate at http://www.gardeningcharlotte.com. Copyright 2013 used with permission by Rolla Daily News - St. James Leader Journal - Waynesville Daily Guide. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. Contact Charlotte at firstname.lastname@example.org.