Climate change, host plant availability, and irrigation shape future region-specific distributions of the Sitobion grain aphid complex.

Background: Understanding where species occur using species distribution models has become fundamental to ecology. Although much attention has been paid to invasive species, questions about climate change related range shifts of widespread insect pests remain unanswered. Here, we incorporated bioclimatic factors and host plant availability into CLIMEX models to predict distributions under future climate scenarios of major cereal pests of the Sitobion grain aphid complex (Sitobion avenae, S. miscanthi, and S. akebiae). Additionally, we incorporated the application of irrigation in our models to explore the relevance of a frequently used management practice that may interact with effects of climate change of the pest distributions.

Results: Our models predicted that the area potentially at high risk of outbreaks of the Sitobion grain aphid complex would increase from 41.3% to 53.3% of the global land mass. This expansion was underlined by regional shifts in both directions: expansion of risk areas in North America, Europe, most of Asia, and Oceania, and contraction of risk areas in South America, Africa, and Australia. In addition, we found that host plant availability limited the potential distribution of pests, while the application of irrigation expanded it.

Conclusion: Our study provides insights into potential risk areas of insect pests and how climate, host plant availability, and irrigation affect the occurrence of the Sitobion grain aphid complex. Our results thereby support agricultural policy makers, farmers, and other stakeholders in their development and application of management practices aimed at maximizing crop yields and minimizing economic losses. © 2023 Society of Chemical Industry.