Abstract
The fall webworm moth, Hyphantria cunea, is a highly invasive defoliator that threatens forest ecosystems in China. The parasitoid wasp Chouioia cunea has been mass-reared and widely released for biological control of H. cunea. Climate change can alter climatic suitability and potentially reshape the spatial matching between hosts and natural enemies, thereby affecting biological control outcomes. Here, we used an ensemble species distribution modeling (SDM) framework to project current (WorldClim 1971-2000) and future (2030s and 2050s) suitable habitats for H. cunea and C. cunea in China under three Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5). We quantified changes in suitable area and host-parasitoid overlap and estimated climatic niche overlap using Schoener's D. Both species were projected to maintain broadly similar suitability patterns with a general northward shift and an increase in total suitable area under several scenarios, leading to extensive overlaps in eastern and central China. Schoener's D (0.738) indicated substantial climatic niche overlap between the two species. Among the retained predictors, the minimum temperature of the coldest month (bio6) and the Human Influence Index were most important for C. cunea. Under SSP5-8.5, overlapping suitable areas were projected to increase to approximately 1.15 million km(2) by the 2050s. These results provided a spatial basis for anticipating where biocontrol releases may be most effective and where potential host-parasitoid mismatches could require strengthened monitoring under climate change.