Synonymy and Color Variation in the Fall Webworm, Hyphantria cunea Drury (Lepidoptera: Arctiidae)

Abstract

Northern and southern specimens of the fall webworm in eastern North America exhibit color differences in both the adult and larval stages, and have often been referred to Hyphantria textor Harris and H. cunea Drury, respectively. However, they will readily inter-breed and produce viable offspring; differences in wing maculation are not discrete and genitalic differences have not been found; differences in the degree of larval pigmentation are not discrete and depend largely on environmental factors; and the nesting and feeding behaviors are similar. It is therefore concluded that the common webworm (larvae with the head and dorsal tubercles black) in both north and south should be referred to H. cunea, which has priority. A sibling species or race (lighter heads and tubercles and different nesting and feeding habits) occurs sympatrically with cunea in the south and also, rarely, in the north; if it has specific status it cannot be referred to either cunea or textor; so textor is relegated to synonymy.