This project sought to identify areas of Canada’s and North America’s growing regions that were now, and could be in the future, under several climate change scenarios, at risk of introduced, invasive insect colonization. List of insects that are in North America and could pose a threat to Canadian agriculture were identified if they cross the border north into Canada (ex. pea weevil in pulses, cereal grass aphids in wheat) or move west from Eastern Canada (ex. pollen beetle in canola), as well as a list of agricultural pests in other countries (ex. yellow blossom midge in wheat) that could threaten Canadian agriculture if introduced to the country. For each of these species, literature search was performed to identify the environmental requirements necessary for these insects to establish in Western Canada. Insect specific biotic and abiotic factors under published current and future climate scenarios were used to determine the ability of the selected insect pests to establish in Western Canada and where each could be distributed in our cropping areas. Due to there being insufficient occurrence data for certain species (ex. The lemon midge), it was not possible to develop species distribution models to predict their establishment under current and future climate change scenarios. Therefore, the research team focused on insects that had adequate information available to create the distribution models. For those with insufficient data, maps were produced showing their current known locations.

Pea aphid was used as a model of North American migration, using environmental response variables such as soil quality (nutrient availability), host crops, elevation, dispersal, and human footprint to model current pea aphid global distribution and then mapped the locations where pea aphid is currently established as a base to model the migration of pea aphids in North America. Using the same modelling approach, hotspots were identified in Canada and throughout the world where there is high likelihood of pea aphid establishment and found that Human influence a major driver of pea aphid distribution. This human influence metric is a combination of nine variables describing human pressure on the landscape. This work on pea aphid migration was published (Hartl et al 2024). Then, following temperature and reproduction experiments conducted in the laboratory with pea aphids, new temperature variables were applied to a “mechanistic” model and compared it to a correlative model, that used less precise data. The results on predicted pea aphid migration under two climate scenarios were different with the mechanistic model, likely coming closer to reality due to its inclusion of these actual temperature responses by pea aphids. This is a noteworthy finding in the insect distribution modelling field which will help pest risk modelers to use our advanced approach in refining their modelling outcomes for early detection and monitoring of pest populations. This work is expected to be published soon (Hartl et al 2025, in prep.).

In wheat, it was determined that the introduced cereal grass aphid is likely to move north from the US into parts of the Canadian prairies under the Shared Socio-economic Pathway (SSP) 585 by 2071-2100. The results indicate a high likelihood of further eastward and southward expansion into the US from the Pacific Northwest (PNW), particularly in wheat and cereal crop-producing regions, posing a threat to crop production. The key environmental drivers for spread of the cereal grass aphid are cropland percentage, temperature, and precipitation, which suggests that future environmental changes will have potential impacts on spread of this insect beyond the PNW. For this portion of the work, the research team established a collaboration with Dr. Sandford Eigenbrode’s laboratory in Oregon where their team has been studying the North American invasion of this wheat pest for 11 years and modeled the likely distribution of this aphid in Canada and concluded that this pest is not likely to establish in most of the wheat growing regions in Canada. A paper has been published on this portion of the project in Crop Protection.

In Canola, one insect pest, the pollen beetle, has established in Eastern Canada, and it’s distribution throughout the world and locations of establishment in Western Canada were modelled. The cabbage stem flea beetle has not invaded North America, and if it does invade, it has the potential to disrupt Winter Canola production, but Spring Canola should be out of synch enough with its lifecycle to be much affected by the canola pest. This modelling was accepted for publication by the Journal of Economic Entomology.

This project sought to develop methods for predicting the locations of introduced insect invasions, using key insect pests as case studies. Species distribution modelling proved to be an effective tool for identifying the region’s most vulnerable to the establishment of these invasive insects under various climate scenarios. These modelling techniques show promise for predicting the potential establishment of insects in new regions when their occurrence records and life history traits from native ranges are available. Additionally, the results show that incorporating physiological requirements of the insect into the models significantly enhances their accuracy. These approaches can also be used to predict future range expansions or contractions of established pests, such as pea aphids, under different climate change scenarios.