OCCURRENCE OF PHYLLOTRETA STRIOLATA, THE STRIPED FLEA BEETLE, IN OPEN PRAIRIE, FOREST, AND PARKLAND OF SASKATCHEWAN (COLEOPTERA: CHRYSOMELIDAE)

Abstract

AbstractIn Saskatchewan the range of Phyllotreta striolata (F.), a pest of parkland rapeseed crops, includes the open prairie in the southwest and the boreal forest in the north. The population of P. striolata on the open prairie is small, with cruciferous weeds being the major host plants. Cruciferous crops grown on the open prairie will almost certainly attract some P. striolata. The population of P. striolata in the forest is substantial, and the range extends northward into arctic regions. Although adults of P. striolata feed upon cruciferous plants growing in the forest, these plants do not appear abundant enough to constitute an adequate food supply. In addition, the identity of the major host plants of the larvae in the forest is unknown. In laboratory experiments, adults of P. striolata were attracted to and attempted to feed upon seven species of forest mosses; however, attempts to maintain a laboratory colony of P. striolata on one of the more abundant mosses were unsuccessful. Forest inhabiting P. striolata attacked rape planted in forest clearings, and therefore probably would infest rape crops grown along the forest edge or in newly cleared areas.