A recent study from the University of Alberta reveals how planting and maintaining treed borders around agricultural fields can provide a significant boost to pollinating and pest-eating hoverflies, ultimately benefiting crop yields and overall ecosystem health.
Hoverflies: Nature’s Dynamic Duo
Conclusion: Hoverflies — A Twofer for Agricultural Crops On the one hand, they work as pollinators when traveling from fields to perimeters for nectar and pollen wrapped up in flowering plants like canola. This pollination can increase agricultural yields by many times.
Hoverfly larvae, by contrast, are predatory on soft-bodied crop pests (e.g. aphids and thrips), providing some natural biological control of these insect pests as well. This makes hoverflies a kind of one-stop-shop for farmers, able to provide both pollinating and pest management services at once.
Treed Borders: A Haven for Hoverflies
Reference: Planting a collection of trees on the edge of fields can increase the numbers of hoverflies in them, as reported in a peer-reviewed study by Valdés1 et al. The researchers found that treed field borders provided more than 33 times as many hoverflies to canola fields compared with grassy borders.
It turns out those treed borders are a far less sterile place for hoverflies, offering more diverse and abundant resources. The trees and shrubs provide wetlands and rotting deadwood, which provides an optimal habitat for female hoverflies to oviposit and their larvae to develop. The treed borders also mean that there is a greater diversity of hoverfly species that can provide additional ecosystem services, beyond those associated with agriculture such as pollination of wildflowers or contributing to soil nutrient cycling.
Conclusion
Our results specify the substantial potential of treed borders to achieve these goals in agricultural landscapes. If farmers can create a space that is more appealing to hoverflies than their current environments, they could also promote enhanced pollination services and better biological control of pests in their crops, increasing yields without having to resort to damaging or toxic pesticides. With increasing landowner interest in using nature-based solutions, the research makes a strong case for incorporating treed field borders to help create and maintain a healthy and more holistic ecosystem.
