Field Guide: tomato hornworms

Sep 4, 2020

A hawkmoth with proboscis unrolled.
Credit Courtesy of Duke Elsner

While no gardener welcomes a tomato hornworm--they eat twice their weight in leaves each day--they are impressive creatures.

 

They pupate underground, six inches underground. Duke Elsner says that’s amazing since caterpillars aren’t really built to tunnel. Then they have to get back out as a moth.  

 

“It’s remarkable how many survive at all in this world,” says the retired MSU Extension educator.

 

As a kid on his uncle’s tomato farm, Elsner would help squash hornworms but not all of them. 

 

“I’d always take a fair share of them home and raise them, try to get some adults, since I was into moths and butterflies from a very young age,” he says.

 

In the spring, a tomato hornworm emerges as a five-spotted hawkmoth, with a wing span as wide as six inches. They hover like hummingbirds while drinking nectar.  And their proboscis is almost as long as their wingspan.

 

“They tend to feed on very deep-throated flowers, although they can use it on shallow flowers, as well,” Elsner says. "It’s pretty remarkable when they unroll it.“

Credit Duke Elsner