(HOST) A new pest has made it’s appearance in commentator Ted Levin’s garden this summer, and he’s wondering why.
(LEVIN) The other day I sent my ten-year-old son Jordan to the the garden to gather salad fixings. The sun, deep in the western sky, cast a rim of yellow light around the plants, transforming backlit tomato leaves into glowing emerald discs. That’s how Jordan first spotted a green, five-inch long, finger-thick caterpillar munching through our tomato plants branch by branch.
Shocked at the size and appetite of the caterpillar and at its menacing red “tail” – a curved spike projecting from the top of the last abdominal segment – Jordan called me into the garden. It was a tobacco hornworm, the larvae of the Carolina sphinx moth, a commercial pest, that feeds on members of the nightshade family, particularly potato, tomato, and tobacco.
I recognized the caterpillar from my boyhood on Long Island; they ate my mom’s tomato plants too. Until now, I had never seen a hornworm in Vermont. According to field guides the tobacco hornworm and the closely related and equally voracious tomato hornworm (it has a black and green spike) are confined to the southern and mid-Atlantic states.
I called my friend Janet Taylor, who owns and runs Crossroads Farms in Post Mills. Crossroads grow tomatoes, plenty of them. Surely they knew about hornworms. Janet Taylor said hornworms first appeared on the farm three years ago. This has been a particularly tough summer.
Why hornworms here and now? Perhaps, it has something to do with global warming – everything else does. We haven’t had a September frost in nearly three years, and the one that came, came late in the month.
A hornworm, either the tobacco or the tomato, over-winter in the soil as pupae. The caterpillars entomb themselves in dark brown cells. Each cell has a distinctive teacup handle arched away from the body, where the sphinx moth’s long tongue (or proboscis) is sheathed. Deep frost can be fatal.
As a group, sphinx moths are fascinating. Most are nocturnal. Some are crepuscular – appearing at dawn or dusk. A few are diurnal. All are big and fast, and appear above the flowers, tongue unfurled like a New Years Eve party favor, hovering in the gloom, pollinating.
I’ve watched sphinx moths sip nectar at twilight in the deep woods of Sharon, visiting one showy orchis after another until the whole patch was pollinated. The bumblebee moth, a dark sphinx with clear forewings, pollinates our flower garden.
And once a number of years ago an astronomical number of five-lined sphinx moth caterpillars fed on a lush and ephemeral bloom of poppies and lupines in the Mojave Desert; I could hear them chew as I walked across the desert floor.
We transfered the hornworms to volunteer tomatoes sprouting in the compost pile. The next morning, only three were left. By afternoon none. The crows, it seems, like them too.
Ted Levin is a writer and photographer and winner of the 2004 Burroughs Medal for Nature Writing.