A guest post by Anne Stine, one our Hubbard Fellows. All photos by Anne.
I adore hummingbirds, and I sometimes bemoan their rarity in my new home here on the Platte. I grew up thinking they were better than fairies- they are cute, ferocious, and they migrate long distances despite their small size. While hummingbirds themselves are scarce in this part of the country, “hummingbird moths” are abundant. Hummingbird moths are so-named because they hover and fly like hummingbirds, sip nectar, and are approximately the same size as hummingbirds. I never noticed hummingbird moths growing up, so since moving here it is as if hummingbirds dropped out of the system and were replaced by enormous insect imposters.
Hummingbird moths, or sphinx moths, are large, furry, and active in the day. Their caterpillars are called “hornworms” because they have what looks to be a long horn extending off their rumps. Most of these larvae have multiple potential food sources. Around here, likely food plants include four o’clocks, wild grapes, elms, and evening primroses1. While some species of hornworms eat crops like tobacco and tomatoes, they are infrequently a pest requiring treatment. In fact, with their propensity to eat undesirables like Siberian elms and weedy species like four o’clocks and evening primrose, one could even characterize them as beneficial.
There are two broods of sphinx moth annually, one emerging in spring and another in fall2. Hornworms pupate in shallow excavations in loose soil1. In the past few weeks I’ve encountered hornworms attempting to dig their burrows in our driveway at the crew house. Of the adults, I see the white-lined sphinx moth (Hyles lineata) most frequently. Twice they have been attracted to my brightly colored clothing (pink shirt, orange shirt). The moths hovered around investigating me for nectar reserves. I’ve seen them feed on a variety of flowers, so they must not be too picky.
Hummingbird moths are an intriguing substitute for hummingbirds. Hummingbird moths are widely distributed across North America, so it would be interesting to learn if their role as pollinators takes on a greater importance in areas where hummingbirds are absent.