Bridging local ecological knowledge and computational modelling to anticipate climate-driven shifts in macadamia stinkbug distribution in Malawi

Stinkbugs (Hemiptera: Pentatomidae) are a significant and growing threat to macadamia production in Malawi. However, the climatic drivers of their distribution and future range dynamics remain poorly understood. Our study integrated ensemble species distribution modelling with farmer insights to map current and projected stinkbug habitat suitability under SSP2-4.5 and SSP5-8.5 emissions scenarios for the 2040s. Precipitation of the warmest quarter (35.3%) and maximum temperature of the warmest month (24.6%) are the dominant environmental variables that influence the suitability of stinkbugs, findings independently corroborated by farmer ecological knowledge. Under baseline conditions, high suitability is concentrated in lowland Rift Valley and lakeshore environments of Malawi, with overlap between stinkbug and macadamia suitability across highland production zones. Under SSP2-4.5, high suitability expands substantially northward, intensifying pest pressure in core production districts. Under SSP5-8.5, near-uniform high suitability dominates across Malawi, eliminating altitude as a spatial buffer and rendering geographically differentiated pest management strategies increasingly obsolete. Our findings highlight the urgent need for climate-smart agroforestry, biological control, irrigation investment, and sustained capacity building to safeguard macadamia as a climate-resilient livelihood asset for Malawi’s farmers, particularly smallholder farming communities.