Classical biological control of the cabbage root fly, Delia radicum , in Canadian canola: an analysis of research needs.

Abstract

Abstract The cabbage root fly (=cabbage maggot), Delia radicum , has increased in importance over the past two decades as a pest of canola (oilseed rape) in Canada. Although D. radicum has been a part of the North American insect fauna for some time, it is not native, so the introduction of natural enemy species from Europe is being considered for integration with existing management strategies. The biology of D. radicum , the injuries it causes to the crop, and strategies already available for its control are briefly reviewed, followed by the process by which Aleochara bipustulata , a predator and parasitoid of D. radicum , was identified as the most promising candidate for introduction in a classical biological control programme. The literature on A. bipustulata and other species in the same genus is then brought together to illustrate the importance of studies to evaluate the potential of A. bipustulata to provide control, and its effects on non-target species.