The seasonality, range and number of agricultural pests is changing as temperatures warm, particularly winter temperatures. These changes are increasing the risk of pest-related damage to agricultural production. Agricultural pests include insects, diseases, weeds and invasive species that impact crop and livestock health. Climate change is also impacting pollinators and beneficial insects. Pollinators play an important role in seed and fruit production as well as crop yield and quality. Pollinators include bees; other insects, such as moths, flies and wasps; and some birds and mammals.
Climate and Other Factors
Climate changes in BC that are contributing to both increasing pest threats and declining pollinator health include: Rising average annual temperatures across all seasons; Increasing growing degree days and growing season length; shifting precipitation patterns, including increasing spring precipitation and increasing extreme precipitation events; and drier summer conditions.
Increasing pest threats
The combined changes in climate can enable existing pest species to increase because they can survive warmer winters. They may also be able to reproduce more often in a single season. As climate zones change, pests can spread further and new species can become established.
Other factors that increase pest-related risk in the province include:
- Introduction of new pests through imported goods or via vehicles, such as aircraft and boats
- Disruption of ecosystem function through loss of habitats and natural predator populations
Declining pollinator health
Changes in temperature and precipitation can also harm pollinator health. Warmer temperatures and extremes can increase pollinator death or reduce reproduction rates. Climate changes may also affect plant-pollinator interactions. For example, plants may bloom at times when pollinators aren’t active or vice versa.
Other factors that decrease pollinator health/habitat in BC include:
- Loss of nectar sources and reduction of pollinator habitat due to a range of human activities
- Increase in pollinator diseases
- Impacts from pollution and/or pesticides
Impacts to Agriculture
Threats from Changing Pest Populations
Changing climate conditions may enable some agricultural pests to flourish. They may also allow pests to impact agriculture through other means. For example, extended dry, hot or wet periods can reduce the health of crops and livestock. This makes them more vulnerable to harmful insect pests and diseases. Crops are also more likely to be damaged when pests emerge at unexpected times or in unexpected areas. As the timing of pest cycles becomes less predictable, some pest management practices will be less effective. And if outbreaks are larger or more frequent, a wider range of strategies, management practices and/or treatments will be needed. As the complexity of pest management grows, so too will the related labour and costs for producers.
Risks from Changing Pollinator Populations
The effects of climate change on specific pollinators and helpful insects are not well understood. But warming temperatures and more extreme conditions are impacting both pollinators and the plants they pollinate. Pollinators are needed for production of most fruits, as well as for vegetable and forage seed production. The combination of changing precipitation and temperatures may narrow or change windows of pollinator activity. Some BC producers manage or rent honeybee hives to improve pollination rates during the critical blossom windows. However, BC is rich in native pollinators, which play an important role in ecosystem health and crop pollination. And at the same time, all types of pollinators are under threat. This includes wild pollinators and commercially produced honeybees. Without enough pollination, crop yields go down and edible plants have a harder time reproducing. About 75% of crops that produce fruit and seeds for human consumption need pollinators to maintain yield and quality.
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Pest & Pollinator Related Projects