Journal of Economic Entomology (2013) 106, 267-276

Rebecca H. Hallett and Mark K. Sears (2013)
Pheromone-based action thresholds for control of the swede midge, Contarinia nasturtii (Diptera: Cecidomyiidae), and residual insecticide efficacy in cole crops
Journal of Economic Entomology 106 (1), 267-276
Abstract: The swede midge, Contarinia nasturtii (Kieffer), is an invasive gall midge causing economic damage to cole crops (Brassica oleracea L.) and other crucifers in eastern Canada and United States. An effective decision-making tool for timing insecticide applications is a critical part of an integrated pest management program against C. nasturtii. Experiments were undertaken over 2 yr and at three locations in southern Ontario to develop pheromone-based action thresholds for C. nasturtii in cabbage and broccoli. An economic comparison between action threshold and calendar insecticide regimes was undertaken. The threshold approach was both economically viable and successful at minimizing swede midge damage for cabbage, and an action threshold of five males per trap per day with a minimum 7 d retreatment interval successfully reduced damage to acceptable levels. However, this approach was not successful with broccoli, which, unlike cabbage, is susceptible to damage by C. nasturtii through all plant stages, including heading. Acetamiprid and λ-cyhalothrin both demonstrated ≈7 d residual activity against C. nasturtii. Registration labels for both insecticides specify a minimum 7 d retreatment interval, which is supported by residual efficacy results. More effective insecticidal products may have longer residual efficacy and improve efficacy of the action threshold approach for broccoli and cabbage.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Rebecca H. Hallett

Research topic(s) for pests/diseases/weeds:
pheromones/attractants/traps
thresholds/decision-support systems

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Contarinia nasturtii	Cabbage (Brassica oleracea)	Canada (east)