Ecological and genomic insights into leafhopper-parasitoid interactions in Canadian agroecosystems under a changing climate

Climate change is altering the balance between pests and their natural enemies in northern agrosystems. Leafhoppers, which are sap-feeders and vectors of plant pathogens, are particularly sensitive indicators of these shifts. Monitoring in Eastern Canada revealed that community composition is closely tied to climate: migratory species increase rapidly above thermal thresholds, while resident species decline under heavy rainfall. We also report the presence in Canada of the corn leafhopper, a Neotropical species whose range is dangerously expanding northward. Conventional insecticides did little to suppress populations, confirming the limits to chemical control. In contrast, native parasitoid wasps were abundant and responsive to seasonal conditions, successfully parasitizing dominant migratory leafhoppers. Genomic analyses also uncovered unexpected diversity, including the first complete mitochondrial genome for a New World Gonatopus , providing valuable tools for biosurveillance. These findings reinforce leafhoppers as sentinels of climate change and point to the conservation of parasitoids as a foundation for climate-resilient pest management.