The western conifer seed bug (Leptoglossus occidentalis) has recently expanded across East Asia, raising concerns regarding its potential impact on cone production and conifer-associated biodiversity. This study aimed to identify suitable habitats and evaluate invasion trajectories under realistic host constraints to support early detection and management. We developed a MaxEnt model using occurrence records and selected environmental variables, restricted predictions by conifer abundance to reflect host availability, and linked suitability to colonization probabilities. These outputs were incorporated into a cellular automaton framework that accounted for local flight dispersal and multiple levels of traffic-mediated long-distance dispersal over a 20-year period. The model identified high suitability across conifer-dominated regions of eastern China, Japan, Korea, and parts of Russia. Simulations indicated that, without long-distance dispersal, spread remained limited and fragmented, whereas even very low probabilities of human-assisted movement produced rapid, discontinuous expansion, and higher probabilities led to a much broader occupation of suitable habitats. These findings suggest that the species poses a substantial risk of establishing across major conifer regions in East Asia, emphasizing the need for proactive monitoring at transportation hubs and targeted protection of biodiversity-relevant conifer forests.
Miao et al. (Mon,) studied this question.