THE WHEAT BULB FLY, DELIA COARCTATA, IN NORTH AMERICA (DIPTERA: ANTHOMYIIDAE)

Abstract

AbstractThe wheat bulb fly, Delia coarctata (Fallén), a widespread Eurasian species, is recorded for the first time from Quebec, New Brunswick, Prince Edward Island, Nova Scotia, and Maine. Unlike most Anthomyiidae, this species overwinters in the egg stage in the soil. Hatching occurs in early spring, and young larvae attack the roots of fall-germinated grasses. The primary host is couch grass, Agropyron repens (Linnaeus). In Europe, however, D. coarctata is an important pest of winter wheat, and workers in North America are alerted to its potential economic importance here. Adults may be distinguished from other root maggot flies by a combination of characters which includes the plumosity of the arista, the setation of the thorax and legs, the colour of the wings and legs, and most importantly, the details of the male and female terminalia.