University:
Washington State University
Course:
ENTOM 101 | Insects and People: A Perspective
Academic year:

2023
Views:

126

Pages:

2
Author:

Sean Horton

Sphinx Moths (Hummingbird Moths) Sphinx moths are rather large moths, and resemble hummingbirds. They are frequently misidentified as hummingbirds at first glance, since they hover over flowers, uncoil, and inject their long sucking mouthparts into the nectaries of plants. They then imbibe the nectar therein – much like hummingbirds. Their wings also beat very rapidly and are seen as nothing more than a blur while these creatures are hovering over their food plants. The most common one we have here in western Washington is the white-line sphinx (Fig. 1) or the striped morning sphinx, Celerio lineata, which is a rather attractive moth. It displays color patterns of pink, brown, white, and black. Some less frequently observed species include the tomato hornworm and the willow hornworm (Fig. 2). Sphinx moths are frequently named for their larval form. The caterpillars of the sphinx moths are extremely large. At maturity, the caterpillars measure about three inches in length. The more common one, the white-lined sphinx moth, may show one of two color forms: usually bright green, and sometimes black on rare occasions. Yellow heads and yellow anal horns cap the caterpillars in their green form. The horns are similar to those of a rhinoceros, only they are positioned at the posterior end of the animal and pointing in the reverse direction. Furthermore, the green color form includes a subdorsal row of pale spots, bordered above and below with a black line and colored spots around the spiracles (breathing holes). Caterpillars with the black color form are usually completely black above, with three yellow dorsal lines and broken black lines on the sides and the bases of the legs. The head and anal horn are also yellow or orange. Two broods of white-lined sphinx caterpillars emerge each year. The caterpillar of the white-lined sphinx moth is quite omnivorous. While sometimes encountered as a pest, a variety of its hosts include weeds. Hence, these caterpillars may become beneficial in the eyes of humans. They rarely cause enough economic damage to merit control in western Washington. The principal hosts for the white-lined sphinx moth include apple, azalea, beets, buckwheat, chickweed, collards, currant, bitterdock, elm, evening primrose, fuchsia, gooseberry, grape, melon, pear, plum/prune, purslane, tomato, turnip, and several other range, forage, and truck plants. The tomato hornworm feeds on tomato and other plants of the Solanaceae family. The willow sphinx moth probably feeds exclusively on willow. When control is necessary, check with your county agent for current chemical practices, or if there are not too many caterpillars, physically destroy the caterpillars by hand or other device. Fig. 1. The adult white-lined Sphinx moth. By A.L. Antonelli. Fig. 2. The larva of the willow hornworm. Note the parasitic wasp prepupae and pupae on the body of the larva. By R.D. Akre.