Over the past week or so, several interesting images have appeared in the “Bug of the Week” guest book. Two of these were fabulous moths belonging to the family Sphingidae, a.k.a. hawk moths, sphinx moths, and hummingbird moths. One sent by Alex was the hummingbird clearwing moth, Hemaris thysbe. Hummingbird moths are beautiful insects as both adults and larvae.r
The adult flies very rapidly to a blossom, inserts a long, straw-like proboscis into to the flower, withdraws nectar in just a few seconds, and flies to the next feeding station. The proboscis of the hummingbird moth is a remarkable structure and in some species, this appendage reaches astonishing length. Charles Darwin discovered an orchid with a nectar receptacle almost a foot from the tubular opening of the flower. He predicted that a species of pollinator with an exceptionally long tongue must have evolved to service the orchid. Although Darwin never observed the pollinator, his prediction proved correct many years later when the giant hawk moth, Xanthopan morganii praedicta, was discovered. Its tongue is more than nine inches long and it is the putative pollinator for the Malagasy orchid. Returning to our hummingbird moth, its favorite flowers are honeysuckle, snowberry, lilac, phlox, bee balm, trumpet vine, vetch, butterfly bush, and thistles. In addition to feeding like a hummingbird, some say that the greenish hairs on the back of the moth resemble the feathers of a ruby throated hummingbird. The flight and feeding behaviors in conjunction with the unusual coloration might be enough to confuse a hungry predator. While a tasty moth might make a fine meal, a predator might think twice about eating a hummingbird. Hummingbird moths are found throughout the United States and venture as far north as Alaska. Hemaris thysbe has two generations in southern states and one in its northern range. After feeding and mating, females lay eggs on the leaves of small shrubs and vines. Honeysuckles, snowberries, viburnums, hawthorns, and cherries are among its favorites.
From the eggs hatch caterpillars that munch leaves. The image of a sphinx moth sent by Cathy is the Pandora sphinx. This beauty likes to visit flowers at dawn and dusk. It lays eggs on Virginia creeper and other members of the grape family. A dramatic horn adorns the rear end of many larval hummingbird and sphinx moths giving these caterpillars the name hornworms. These wonderful moths are relatives of the tomato hornworm that we met in a previous episode of Bug of the Week “Horning in on your tomatoes", September 26, 2005.
Special thanks to Alex and Cathy for sharing images that were the inspiration for this Bug of the Week. To learn more about hummingbird, hawk, and sphinx moths, please visits the following web sites.