Swede Midge (Diptera: Cecidomyiidae), Ten Years of Invasion of Crucifer Crops in North America

Abstract

The Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), a common insect pest in Europe, is a newly invasive pest in North America that constitutes a major threat to cruciferous vegetable and field crops. Since its first identification in Ontario, Canada, in 2000, it has rapidly spread to 65 counties in the provinces of Ontario and Quebec and has recently been found in canola (one of two cultivars of rapeseed, Brassica napus L. and Brassica campestris L.) in the central Prairie region where the majority of Canada's 6.5 million ha (16 million acres) of canola is grown. The first detection of Swede midge in the United States was in 2004 in New York cabbage (Brassica oleracea L.), but it has now been found in four additional states. Here, we review the biology of Swede midge, its host plant range, distribution, economic impact, pest status, and management strategies. We provide insight into this insect's future potential to become an endemic pest of brassica crops in North America. We also proposed research needed to develop tactics for handling this invasive pest in brassica crops.

Biology and development ofAcrolepiopsis assectella(Lepidoptera: Acrolepiidae) in eastern Ontario

“…Insecticides will play an important role in a control strategy for this pest of high value vegetable crops, and this has been demonstrated in the case of swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidoymiidae) (Chen 2011), another newly introduced pest of vegetables from Canada. Cornell University petitioned the New York State Department of Environmental Conservation (NYSDEC), and was granted 2(ee) emergency exemptions, for 5 insecticides for control of A. assectella in 2010 based on the immediate threat of A. assectella.…”

Patterns of diapause frequency and emergence in swede midges of southern Ontario

“…After approximately 3 weeks of growth, broccoli flats were hardened outdoors for 1 week before transplanting to the field plot. Broccoli plantings were spaced temporally to ensure optimal availability of ovipositing sites (pre‐headed plants) throughout the growing season (Baur & Rauscher, ; Chen et al , ). Four‐week old seedlings were transplanted into the field, 45 cm apart, in five adjacent rows covering a 5 × 26 m 2 block on 28 May, 28 June and 28 July with a spacing of 1 m between each row and block.…”

“…The swede midge Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae) is an invasive agricultural pest in North America with a rapidly expanding range (Hallett & Heal, ; Chen et al , ). Swede midge larval feeding causes swelling and distortion of meristematic plant tissues, resulting in considerable damage to economically important crops of Brassica oleracea L. (including broccoli, cauliflower, cabbage, Brussels sprouts, collard greens and kale), as well as Brassica rapa L. and Brassica napus L. (which includes turnips, rutabagas and canola) (Barnes, ; Stokes, ; Hallett & Sears, ).…”

“…Swede midge larval feeding causes swelling and distortion of meristematic plant tissues, resulting in considerable damage to economically important crops of Brassica oleracea L. (including broccoli, cauliflower, cabbage, Brussels sprouts, collard greens and kale), as well as Brassica rapa L. and Brassica napus L. (which includes turnips, rutabagas and canola) (Barnes, ; Stokes, ; Hallett & Sears, ). Yield losses of 85–100% resulting from swede midge damage have been reported for heavily infested crops (Hallett & Heal, ; Chen et al , ) and swede midge presents an on‐going threat to the billion‐dollar Brassica industries of Canada and the U.S.A. (Kikkert et al , ; Olfert et al , ). Since swede midge‐attributed crop damage was first identified in Ontario in 1996 (Hallett & Heal, ), populations have spread throughout southeastern Canada (Canadian Food Inspection Agency, ), to some regions of the Prairies, and to north‐eastern regions of the U.S.A. (Chen et al , , ; Hallett et al , ).…”

“…Yield losses of 85–100% resulting from swede midge damage have been reported for heavily infested crops (Hallett & Heal, ; Chen et al , ) and swede midge presents an on‐going threat to the billion‐dollar Brassica industries of Canada and the U.S.A. (Kikkert et al , ; Olfert et al , ). Since swede midge‐attributed crop damage was first identified in Ontario in 1996 (Hallett & Heal, ), populations have spread throughout southeastern Canada (Canadian Food Inspection Agency, ), to some regions of the Prairies, and to north‐eastern regions of the U.S.A. (Chen et al , , ; Hallett et al , ). The swede midge exhibits facultative diapause and overwinters in the third‐instar larval stage in spherical cocoons below the soil surface (Readshaw, ).…”