OBSERVATIONS ON THE BIONOMICS OF SOME NORTHERN SPECIES OF TABANIDAE (DIPTERA)

Abstract

Ten species of Tabanus, five of Chrysops, and one of Atylotus are recorded from the Churchill, Manitoba, area. Of these, Tabanus itasca Philip, Tabanus sp. (new?), and Atylotus ohioensis (Hine) represent new records. It is established that Tabanidae in this region overwinter in the larval stage and that most species have at least a three-year life cycle. Problems in taxonomy are discussed. Methods of rearing the immature stages, of collecting adults emerging in the field, of estimating larval and adult populations, and of correlating adult activity and weather conditions are described, and the results are presented. Larvae of the tipulid Prionocera dimidiata (Lw.) are reported as predators of larvae of Chrysops spp. The emergence of the chalcid parasite Diglochis occidentalis (Ashm.) from pupae of Tabanus and Chrysops spp. reared from the larval stage is recorded.