A Behavioral Study of Two Races of the Fall Webworm, Hyphantria cunea, (Lepidoptera: Arctiidae) in Louisiana

Abstract

Fall webworms, Hyphantria cunea (Drury), found in Louisiana differ in appearance and morphology. Those designated as an “orange race” construct compact nests. Nests of the black race are diffuse and generally subdivided into several small nests. The “black race” infests 34 hosts, of which sweetgum, persimmon, and willow seem to be preferred, and the “orange race” infests 7 hosts, of which pecan and persimmon are preferred. Adults of the two forms will cross in the laboratory and produce viable Fi and F2 progeny. There are considerable clifferences in manner of egg deposition and larval behavior.