Sphinx Moths
Recently, Master Gardeners received an email asking about beautiful moths seen hovering like hummingbirds. The writer was concerned that, not having seen these creatures before, they might be new, invasive arrivals. One of the benefactors of last winter’s ample rainfall and lush plant growth was the native beneficial Sphinx Moth, aka hummingbird moth or hawk moth.
The U.S. Forest Service website compares hawk moths or sphinx moths to their “respectable” cousin, the butterfly. “Unfortunately, we usually vilify moths because of their association with the dark of night and our innate fear of darkness and things that go bump in the night.” Some sphinx moths do fly only at night, but this year the Mother Lode was abuzz with moths that appeared in the afternoon and at dusk to gather nectar.
Belonging to the insect family Sphingidae, part of the Order Lepidoptera (butterflies and moths), the caterpillars of these native creatures are often referred to as “horn worms” for the long protuberance at their rear. They are cousins to our ubiquitous, and often despised, tomato hornworms whose parents are, indeed, sphinx moths. Some are so seldom seen—such as the Sonora Sphinx Moth that lives only in oak woodlands bordering the Sonoran Desert in Arizona and Northern Mexico—that only one sighting may be reported in any given year!
These acrobatic, fast flyers can hover, hum, and dart like hummingbirds. When I saw the first one this summer, I thought I was looking at an unrecognized hummingbird! Then I felt fortunate to see one individual feeding on salvia. Soon, there were many moths zipping through the canopy of the blooming desert willow.
According to “The Laws Guide to the Sierra Nevada,” several of these beneficial pollinators can be found in the Sierra. Many of them feed on native California plants such as broadleaf trees (a reason to protect our California oaks), willows, rose and manzanita. My prolific grapevines may have provided caterpillar food for the Achemon Sphinx which lives in woodland and scrubby environments from Maine to California. The White-lined Sphinx took up residence in my yard in Jamestown this year, while the Ceanothus Silk Moth can be found from British Columbia to Baja. A beautiful, red-brown moth with large white “comma” marks on its wings, its caterpillars eat manzanita, buckbrush, willow, gooseberry, madrone and mountain mahogany.
If you’re digging in your garden this winter and find a fat, dark-brown, short, cigar-shaped “thing,” avoid the temptation to squash it. You are looking at the chrysalis/winter-hibernation stage of a sphinx moth. Some species pupate in the soil during the winter; others form cocoons attached to plant stalks.
The California Native Plant Society website, Calscape, shows beautiful photos of the White-Lined Sphinx with its native range extending the length of California. Entering a physical location into the address search box will return a list of host plants. Planting a “moonlight garden” of pale, night-blooming flowers may allow you to see the nocturnal cousins at work. Fragrant tubular flowers with ample amounts of nectar such as salvias and desert willow may attract the diurnal cousins for a breath-taking display.
Rebecca Miller-Cripps is a University of California Cooperative Extension Master Gardener of Tuolumne County.
