Seasonal Development of an Invasive Exotic Species,Contarinia nasturtii(Diptera: Cecidomyiidae), in Quebec

Abstract

The seasonal development of the swede midge Contarinia nasturtii Kieffer was studied in Quebec in 2004 and 2005 using pheromone traps, emergence cages, and visual inspection in relation to degree-day accumulations (DD7.2 degrees C). Peak emergence of overwintering adults occurred between 344 and 731 DD7.2 degrees C (second half of June) during both seasons. The swede midge had three to four overlapping generations in Quebec based on adult captures in pheromone traps and abundance of larvae in the field. The level of infestation was higher in late transplants than in early transplants, with cauliflower and broccoli being more susceptible to damage than white or red cabbage under high pest population.

The parasitoid complex associated with the invasive swede midge, Contarinia nasturii Kieffer (Diptera: Cecidomyiidae) in Europe : prospects for classical biological control in North America

“…In southern Ontario, 3-4 generations of swede midge with two overwintering emergence phenotypes have been reported Hallett et al 2009b). Similarly, Corlay & Boivin (2008) found evidence for 3-4 overlapping generations in Quebec based on larval counts and pheromone trap data. In Canada, similar to Europe, first emergence of adult swede midge usually occurs in midto late May, with overwintering emergence peaking in early to mid-June (Corlay and Boivin 2008;Hallett et al 2009b).…”