The box-tree moth Cydalima perspectalis (Walker) is an invasive pest causing severe damage to box trees (Buxus spp.). It is native to Japan, Korea and China, but established populations have been recorded in a number of locations across Europe since 2007 and the spread of the insect continues. The developmental investigations suggest that larvae overwinter mainly in their 3rd instar in Europe and that diapause is induced by a day length of about 13.5 h. One and a half to 2 months in the cold are necessary to terminate diapause. Threshold temperatures for development and number of degree-days to complete a generation are slightly different from those calculated in previous studies in Japan. A bioclimatic (CLIMEX â ) model for C. perspectalis in Europe was developed, based on climate, ecological and developmental parameters from the literature and new field and laboratory studies on diapause termination, thermal requirements and phenology. The model was then validated with actual distribution records and phenology data. The current distribution and life history of C. perspectalis in Europe were consistent with the predicted distribution. The climate model suggests that C. perspectalis is likely to continue its spread across Europe, except for Northern Fenno-Scandinavia, Northern Scotland and high mountain regions. The northern distribution of C. perspectalis is expected to be limited by a number of degree-days above the temperature threshold insufficient to complete a generation, whereas its southern range is limited by the absence of a cold period necessary to resume diapause. The model predicts relatively high Ecoclimatic Indices throughout most of Europe, suggesting that the insect has the potential of becoming a pest in most of its predicted range. However, damage is likely to be higher in Southern and Central Europe where the moth is able to complete at least two generations per year.

Climate change may dramatically affect the distribution and abundance of organisms. With the world's population size expected to increase significantly during the next 100 years, we need to know how climate change might impact our food production systems. In particular, we need estimates of how future climate might alter the distribution of agricultural pests. We used the climate projections from two general circulation models (GCMs) of global climate, the Canadian Centre for Climate Modelling and Analysis GCM (CGCM2) and the Hadley Centre model (HadCM3), for the A2 and B2 scenarios from the Special Report on Emissions Scenarios in conjunction with a previously published bioclimatic envelope model (BEM) to predict the potential changes in distribution and abundance of the swede midge, Contarinia nasturtii, in North America. The BEM in conjunction with either GCM predicted that C. nasturtii would spread from its current initial invasion in southern Ontario and northwestern New York State into the Canadian prairies, northern Canada, and midwestern United States, but the magnitude of risk depended strongly on the GCM and the scenario used. When the CGCM2 projections were used, the BEM predicted an extensive shift in the location of the midges' climatic envelope through most of Ontario, Quebec, and the maritime and prairie provinces by the 2080s. In the United States, C. nasturtii was predicted to spread to all the Great Lake states, into midwestern states as far south as Colorado, and west into Washington State. When the HadCM3 was applied, southern Ontario, Saskatchewan, and Washington State were not as favourable for C. nasturtii by the 2080s. Indeed, when used with the HadCM3 climate projections, the BEM predicted the virtual disappearance of 'very favourable' regions for C. nasturtii. The CGCM2 projections generally caused the BEM to predict a small increase in the mean number of midge generations throughout the course of the century, whereas, the HadCM3 projections resulted in roughly the same mean number of generations but decreased variance. Predictions of the likely potential of C. nasturtii spatial spread are thus strongly dependent on the source of climate projections. This study illustrates the importance of using multiple GCMs in combination with multiple scenarios when studying the potential for spatial spread of an organism in response to climate change.

No abstract

The swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), is a pest of most cultivated Brassicaceae such as broccoli, canola, cauliflower, cabbage, and Brussels sprouts. The species primarily has a Palaearctic distribution and occurs throughout Europe and southwestern Asia to the Caucasus. Between 1996 and 1999, producers of cruciferous vegetables in Ontario, Canada, reported crop damage that was consistent with damage symptoms characteristic of C. nasturtii feeding and in 2000, field studies confirmed that this damage was caused by C. nasturtii . A bioclimatic model was developed to predict potential range and relative abundance of C. nasturtii in Canada in order to determine the impact of the establishment and spread of C. nasturtii populations. Model output indicated that C. nasturtii could potentially become established in all provinces of Canada, with the risk being greatest in southwestern British Columbia, southern Ontario and Quebec, New Brunswick, Nova Scotia, and Prince Edward Island. Results indicated that C. nasturtii population growth in the Prairie Ecozone of western Canada would be greatest in years with above average precipitation.

The swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), is a pest of cruciferous crops (Brassicaceae) in Europe and North America with high potential for economic impact. Effective timing of insecticide applications for swede midge control is difficult, in part due to a short adult lifespan. Predictive models are often used in integrated pest management programmes to facilitate the timing of control strategies. A European model, Contapré, for predicting adult swede midge emergence was shown to be inaccurate under Ontario field conditions. A new predictive model, MidgEmerge, was developed using DYMEX TM modelling software. MidgEmerge accurately predicts swede midge emergence in both Ontario and Québec. Observed emergence patterns cannot be explained without the presence of multiple emergence phenotypes. MidgEmerge indicates that there are two emergence phenotypes of the swede midge, each completing four generations per year in southern Ontario. A fifth generation of each may become possible with climate change. Evidence of a possible third emergence phenotype is presented. MidgEmerge has the potential to be an important predictive tool to inform and direct integrated pest management practices targeted against swede midge in North America.

Climate is the dominant factor determining the distribution and abundance of most insect species. In recent years, the issue of climatic changes caused by human activities and the effects on agriculture has raised concern. General circulation model scenarios were applied to a bioclimatic model ofMelanoplus sanguinipesto assess the potential impact of global warming on its distribution and relative abundance. Native to North America and widely distributed,M. sanguinipesis one of the grasshopper species of the continent most responsible for economic damage to grain, oilseed, pulse, and forage crops. Compared to predicted range and distribution under current climate conditions, model results indicated thatM. sanguinipeswould have increased range and relative abundance under the three general circulation model scenarios in more northern regions of North America. Conversely, model output predicted that the range of this crop pest could contract in regions where climate conditions became limiting.

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.

Cereal leaf beetle, Oulema melanopus L., is an invasive pest insect of small grain cereal crops, particularly oat, wheat, and barley. The first report of cereal leaf beetle populations in North America came from Michigan in 1962. Surveys indicate that populations have become established throughout eastern North America from Ontario to Alabama and in northwestern North America from Utah to southern British Columbia. The establishment of O. melanopus in western North America has raised concern that its presence is a potential risk to the Canadian cereal industry, especially in the prairie ecozone of western Canada, where up to 10 million hectares of cereal crops are grown annually. Field surveys to date have indicated that O. melanopus has not yet become established in this region. A CLIMEX™ model for O. melanopus in North America was developed, based on climate and ecological parameters, and validated with actual distribution records. The actual distribution of O. melanopus in eastern North America matched the predicted distribution well. The model predicts that, once introduced, O. melanopus would readily survive in the cereal-growing areas of western Canada and present a significant risk to cereal production. The potential for establishment of O. melanopus in the prairie ecozone of western Canada substantiates the efforts by regulatory agencies to prevent accidental introduction of this pest species.