Leafhoppers as markers of the impact of climate change on agriculture

Climate change is reshaping agriculture and insect biodiversity worldwide. With rising temperatures, many insect species are expected to be pushed beyond their current thermal limits, and losses related to herbivory and diseases transmitted by them will be experienced in new regions. Here, we propose that climate change’s impact on agriculture can be forecast by studying migratory leafhoppers. From 2021 to 2022, we measured leafhopper numbers in eastern Canada's strawberry fields to test our hypothesis, observing that leafhopper species and phytoplasma disease-affected strawberry plants both doubled, trends influenced by temperature changes. A further post-insecticide application study reveals that insecticides used by strawberry growers could be ineffective in controlling leafhopper populations, possibly due to changes observed in their microbiome. Our research provides evidence that leafhoppers are sensitive to the effects of climate change, making them ideal markers to research the effect of climate change on agriculture. Science for society: We have reached a critical tipping point in the climate crisis, requiring us to fully use our resources to stop the progression of global warming and its devastating effects. Agriculture, a top contributor to greenhouse gas emissions, accounts for 8%–10% of total emissions in Canada and the United States. The escalation of pest invasions, a consequence of global warming, threatens food security in the typically cold northern hemisphere and exacerbates agriculture's impact on climate change by increasing pesticide usage. This study examines the effects of climate change on agriculture using leafhoppers—an insect pest group and disease vectors. We found that leafhopper abundance, migration, and microbiome are sensitive to the effects of climate change and that their control will be increasingly challenging. Our findings indicate that leafhoppers can serve as sentinels of climate change, presenting an opportunity to reduce insecticide usage and promote sustainable agriculture practices.