Contarinia nasturtii (Kieffer)
First occurrence of the swede midge in North America
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Name: Contarinia nasturtii (Kieffer)
Animalia: Arthropoda: Insecta: Diptera: Cecidomyiidae
Common Names: Swede midge; cabbage midge; cabbage crowngall fly (Netherlands); cecidomia de la col (Spanish); cecidomie du chou-fleur (French)
In 2000, Canadian researchers determined that damage observed on broccoli (Brassica oleracea L. var. italica) in Ontario since 1996 and attributed to nutrient deficiencies, was instead that caused by swede midge, a pest previously known only from Palearctic regions. Non-definitive surveys in 2000 and 2001 resulted in nine positive counties in Ontario, some of which are contiguous with New York State (U.S.A.), and one in Quebec.
Issues of Concern: Contarinia nasturtii is a serious pest of cole crops--between 1996 and 1999, midge damage accounted for up to an 85% loss in marketable yield in some Ontario fields. In addition, preliminary research suggests that three to four generations, possibly overlapping, occur in Ontario, with adults emerging between late May and early September. Swede midge deposits its eggs on the vegetative and generative tissue of cruciferous plants, where the feeding larvae's salivary secretions twist and deform the plant tissue.
Presumably, this pest could spread on vegetative material of cruciferous crops.
Hosts: Primary hosts of C. nasturtii are members of the family Brassicaceae, including broccoli, cauliflower (B. oleracea var. botrytis), cabbages (B. oleracea var. capitata), and radish (Raphanus sativus).
Canada (Ontario, Quebec); Europe (widespread)
A characteristic symptom of Swede midge infestation is "blindness" where the broccoli or cauliflower head would form. "Blindness" is the disruption or lapsing of growth at the terminal growing point of the plant. In older plants, Swede midge larval feeding results in the distortion or loss of the broccoli or cauliflower head.
Hallett, R.H., and J.D. Heal. 2001. First nearctic record of the swede midge (Diptera: Cecidomyiidae), a pest of cruciferous crops from Europe. The Canadian Entomologist 133: 713-715.
Warning: The information in this archived item was not confirmed with the appropriate National Plant Protection Organization and is provided solely for informational purposes. Please use this information with caution.