- Author: Kathy Keatley Garvey
Frankly, the garden's not big enough for both of you, and one of you has to go. It's not you. It's the hornworm.
"This one is nobody's friend if you're a gardener and like to grow tomatoes," says entomologist Jeff Smith, curator of the Bohart Museum of Entomology's Lepidoptera collection, in his recently posted video showcasing the hornworm and its adult form, the sphinx moth (Sphingidae family).
Smith is presenting a series of short videos on the "different aspects of the collection of moths and butterflies."
In this video, Smith relates how the hornworm got its name: There's a "horn" at the end of its abdomen that looks like "a little spike." The tobacco hornworm (Manduca sexta) and tomato hornworm (Manduca quinquemaculata) are quite similar, he points out. Both are pests on tomatoes and are often labeled as "tomato hornworms."
The origin of the name, the sphinx moth? "When the larva or caterpillar is disturbed, it rears up into an Egyptian sphinx-like pose," Smith says.
However, good luck finding hornworms. "They are so well camouflaged, that it takes forever to find them," Smith says. One way to know they're there is "because they make a piece of poop (frass) about as big as a pea," Smith says.
When the caterpillars are attacked, "they spit tomato juice on you, which doesn't taste good."
The UC Statewide Integrated Pest Management Program (UC IPM) says this about hornworms: "Hornworms feed on blossoms, leaves, and fruit. At high populations they can extensively defoliate plants and scar the fruit. They are rarely a problem in the warmer interior valleys unless natural enemies are disrupted, in which case, they can do serious damage. They are mostly problems in garden situations."
The Bohart Museum of Entomology also offers online information sheets, the work of Lynn Kimsey, director of the Bohart and a UC Davis distinguished professor of entomology. (The directory of subjects is here.)
"The larval stage (caterpillar) feeds primarily on tomatoes, but it also is known to attack other crop plants in the Solanaceae, including egg plants, peppers, and potatoes," Kimsey noted. "When the caterpillars are numerous, they can do extensive damage in a short time. The caterpillars feed on the upper portions of leaves and new stems, and occasionally, when the caterpillars are numerous, it will feed on the tomato fruit as well. They tend to remain out of direct sunlight, and so are found near the main stem of the plant during the day. They are more easily spotted when they move to the outer portions of the plant at dusk and dawn. Their presence is often first recognized by an excessive amount of frass (droppings) around the base of the plant. The hornworm caterpillar is 3½-4 inches (9-10 cm) long and pale green, with white and black markings." (Read more about the Bohart Museum's information on hornworms here.)
Meanwhile, have you ever been up close and personal to a hornworm?
We don't have any in our garden, so we borrowed a hornworm from a neighbor whose garden thrives with tomatoes and peppers. She plucked it off a pepper plant. "It seems to like the pepper plant better than the tomato," she said.
Perhaps this one will grow to adulthood? Apparently it's a tobacco hornworm as it has a red-tipped horn. "Tomato hornworms have eight V-shaped white markings with no borders; tobacco hornworms have seven white diagonal lines with a black border. Additionally, tobacco hornworms have red horns, while tomato hornworms have dark blue or black horns," according to Wikipedia. The tobacco hornworm turns into a Carolina sphinx moth or, generally, a hawk moth. The tomato hornworm turns into a sphinx moth commonly known as a sphinx, hawk, or “hummingbird” moth.
(Editor's Note: The Bohart Museum, located in Room 1124 of the Academic Surge Building on Crocker Lane, UC Davis, is the home of nearly eight million insect specimens; a live "petting zoo," comprised of Madagascar hissing cockroaches, stick insects and tarantulas; and a gift shop. The Bohart is temporarily closed due to the COVID-19 pandemic precautions but the gift shop is online.)
- Author: Kathy Keatley Garvey
She has no formal training in the science of insects, but she can catch insects with the best of 'em. Plus, her credentials include a butterfly mark on her leg.
Xena the Warrior Princess is a rescue cat. We first spotted her outside a Costco store in the winter of 2000, the same year our son headed off to college to study computer science and mathematics.
A sign proclaimed "Free kitten!"
Not wanting a kitten, free or not (we already owned an adventuresome calico named Indiana Joan), we started to walk away.
But she was calling my name, this scrawny kitten dressed unabashedly in the same tuxedo colors our son wore while playing double bass for the Sacramento Youth Symphony's Premier Orchestra.
Coincidence? Probably. Fate? Perhaps. Serendipity? Certainly.
I thought about naming her "Free," but husband Jim didn't think that would be such a great idea. You just can't step out on the front porch and yell "Free! Free! Free!"
So Xena the Warrior Princess she became: half-warrior, half-princess, and all kitten. At first, Xena repeatedly performed sofa-to-chair leaps in the family room--antics that prompted friend Marilyn to observe: "I think her mother had an affair with a flying squirrel."
Then came the insects. The butterflies, the beetles (not the kind that play music) the honey bees, the sunflower bees, the carpenter bees and the moths.
(We will not talk about the roof rat and the flicker. They are not insects.)
Every night, or so it seems, our feline entomologist snares a hornworm moth and eagerly shares it with us. UC Davis entomologist (and apiculturist) Eric Mussen says the mangled specimen (below) is either a tomato hornworm or tobacco hornworm.
At least it's not a flying squirrel.