Published online by Cambridge University Press: 31 May 2012
In the course of investigations of the cabbage maggot, Delia radicum (L.) (= brassicae Wiedemann, brassicae Bouché), a pest of canola (rapeseed) in northern Alberta, an epidemic of the parasitic fungus Strongwellsea castrans Batko and Weiser (see Humber 1976) was documented during July 1983. Infected flies (mostly females) can be recognized by the presence of one or more cavities in the abdominal membrane, into which the fungus discharges its spores (conidia). The flies continue to feed (as vital organs are not attacked), but their eggs fail to mature, apparently because of inadequate nutrition. The presence of this fungus as a pathogen of the cabbage maggot in Canada is well known (Nair and McEwen 1973).