AbstractThe 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.
摘要 1995 年,人们在阿尔伯塔省南部发现卷心菜象鼻虫(Ceutorhynchus obstrictus (Marsham) )为害油菜[Brassica napus L. and Brassica rapa L. (Brassicaceae)] ,到 1999 年,其种群数量已达到爆发密度。这种象鼻虫在南部大草原的耕地中迅速扩散,促使本研究评估其在加拿大油菜花生产的主要地区潮湿混合草地和杨树公园生态区建立的潜力。在这项研究中,对卷心菜象鼻虫的短期(24 小时)和长期(4 年)分布模式进行了研究,并将这些数据与以前发表的生态学研究结果和 CLIMEX™ 软件中的气象数据相结合,预测加拿大西部可能发生具有重要经济意义的虫害的地区。在油菜花蕾和花期的 24 小时内,成虫的时间分布仍主要局限于花序,而不是茎和叶,与一天中的任何时间无关。根据 1997 年至 2000 年在商业油菜田进行的调查记录,该物种从最初发现它的艾伯塔省南部地区迅速向北部和东部扩散。传播速度约为 55 公里/年,2000 年首次在萨斯喀彻温省发现了 C. obstrictus 种群。根据 CLIMEX™ 模型预测,C. obstrictus 的分布最终将覆盖加拿大西部的整个油菜籽生产区。