Disease in a Field Population of the Introduced Essex Skipper, Thymelicus lineola (Ochs.) (Lepidoptera: Hesperiidae)

Abstract

The Essex skipper, Thymelicus (Adopaea) lineola (Ochs.), is said to have been introduced from Europe to the area of London, Ontario, about 1910 but attracted Iittie attention until 1955 (MacNay, 1956). Since then it has been found over most of southern Ontario (MacNay, 1959) and presently is causing damage to fields of timothy, Phleum pratense L., near Priceville, Ontario. As the larvae eat the leaves of timothy and orchard grass, Dactylis glomerata L., this species is a potential pest of forage crops.