23 August 2007

Where is a Cotesia when you need one?


I discovered late this afternoon that someone had been munching on the leaves of our tomato plants and leaving behind feces. How rude! The guilty party was soon spotted on a green branch pretending to be a green branch. It was a tobacco hornworm, the caterpillar of the Carolina sphinx (Manduca sexta).

tobacco hornworm1

The interesting thing is that there is also a tomato hornworm, which is the caterpillar of the five-spotted hawk moth (Manduca quinquemaculata). From Wagner*:

...the common names Tobacco Hornworm [are used] to refer to this species [Manduca sexta] and Tomato Hornworm for M. quinquemaculata, I wish it were not so, because it is this sphinx that I invariably find on my tomatoes.

So we have the same situation in our backyard, the tobacco hornworm on the tomatoes. Wagner continues:
Caterpillars are attacked by a braconid wasp (Cotesia congregata) that lays dozens of eggs within each larva [=caterpillar]...The host caterpillar is doomed, consigned to a slow death that may not follow for weeks.

I am keeping my fingers crossed. In the meantime, here is the horn end of the tobacco hornworm.

tobacco hornworm2

The follow-up post is here.

*David L. Wagner, Caterpillars of Eastern North America, Princeton Field Guides, 2005.


umit said...

What a horny little. Can it be a possibility that the other species is local?

Frank Anderson said...

Oh, you had a great chance to use one of my favorite words and you passed it by -- those caterpillar droppings are frass. What a fine word. I think it would make a particularly nice (and fairly inoffensive) curse word.


Frass! Now, I know...