Fly may be depleting U.S. giant silk moths

Some of the giant silk moths of North America are taking a beating because an early 20th-century attempt to control another insect went bad, researchers in Massachusetts suggest.

Adult cecropia moth (above) and promethea moth may be losing ground against an imported parasitic fly. Boettner and Stephen Thomas

Cecropia moths, with wing spans of up to 5 inches, fall prey in substantial numbers to a parasitic fly first brought to the United States to rein in gypsy moths, report George H.