The Canadian Entomologist (2002) 134, 403-418

L.M. Dosdall, R.W. Weiss, O. Olfert and H.A. Cárcamo (2002)
Temporal and geographical distribution patterns of cabbage seedpod weevil (Coleoptera: Curculionidae) in canola
The Canadian Entomologist 134 (3), 403-418
Abstract: The cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), was discovered infesting canola [Brassica napus L. and Brassica rapa L. (Brassicaceae)] in southern Alberta in 1995, and by 1999 its populations had reached outbreak densities. The weevil has dispersed rapidly through cropland in the southern prairies, prompting this study to assess its potential for establishment in Canada's primary region of canola production in the Moist Mixed Grassland and Aspen Parkland ecoregions. In this study, both short- (24 h) and long-term (4 years) distribution patterns of cabbage seedpod weevil were examined, and these data were combined with previously published ecological findings and meteorological data in CLIMEX™ software to predict regions of western Canada where economically important infestations are likely to occur. Adult temporal distributions over 24 h on canola in bud and flower remained restricted primarily to the inflorescence rather than on stems and leaves regardless of time of day. Surveys conducted in commercial canola fields from 1997 to 2000 recorded rapid dispersal of the species to the north and east from the region of southern Alberta where it was initially found. Dispersal occurred at a rate of approximately 55 km/year, and in 2000 C. obstrictus populations were found in Saskatchewan for the first time. The CLIMEX™ model predicts that the distribution of C. obstrictus will eventually encompass the entire region of canola production in western Canada.
(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): Lloyd M. Dosdall, Owen Olfert, Héctor A. Carcamo

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ceutorhynchus obstrictus	Rape/canola (Brassica napus)