THEY’VE ALREADY STARTED on the fall cleanup. The tobacco hornworms, or Manduca sexta, that is–who love to chomp late in the garden season here on my haze of self-sown Nicotiana, or flowering tobacco–the annuals I let spread themselves around for my visual pleasure and to attract hummingbirds. But how do I know these voracious giant green caterpillars aren’t actually their close cousins the tomato hornworms, Manduca quinquemaculata (since both species will eat Solanaceous crops such as tobacco and tomato)? It’s all in the stripes, and the “horns.”
The tomato hornworm and tobacco hornworm both have angled white markings on their sides, but the tobacco hornworm’s seven marks just go in one direction, and the white is edged in black; the tomato hornworm’s eight marks per side are each more like a chevron, or “V,” with no black edge. The other big difference: Tobacco hornworms’ “horns” (which look like a tail) are usually reddish; the tomato hornworms’ are black or blue-black. (Oddly, I don’t have a photo of the tomato hornworm, but you can compare them on this University of Florida web page.)
That University of Florida Entomology site has photos of the very similar-looking sphinx moths that each one becomes, too.
I think the one just above was more recently “hatched,” because its body was still dark-colored, but I’m not certain. Maybe he’d just been smoking and got all sooty? (Kidding.) You can see all the life phases–caterpillar, chrysalis, sphinx moth–here.
I have to say, I’m violent when one of these guys is eating my tomatoes in early summer, and it’s all “off with their heads” over here then. But in fall, as the garden unwinds anyhow? Eat all you want; the buffet is open. Go ahead and get fat and juicy, tobacco hornworms–and maybe some bird will eat you!