Stand and Landscape Drivers of Trap Captures of the Pine Wilt Disease Vector Monochamus alternatus (Coleoptera: Cerambycidae) in the Qinling Mountains.

Monochamus alternatus (Coleoptera: Cerambycidae) is the principal vector of pine wilt disease, one of the most destructive forest diseases affecting conifer ecosystems in East Asia. However, the relative roles of stand structure and surrounding landscape context in shaping spatial variation in trap captures of this vector in mountainous forests remain poorly understood. The associations of stand- and landscape-level factors with trap captures of M. alternatus were assessed in the Qinling Mountains of central China, a topographically complex region experiencing rapid expansion of pine wilt disease. Twenty pine forest plots were monitored with pheromone traps from April to October 2023, and stand characteristics and landscape variables were quantified at multiple spatial scales. Generalized linear models and multimodel inference showed that the proportion of Pinus massoniana within stands was significantly positively associated with beetle trap captures, whereas the proportion of construction land within a 250 m radius was strongly negatively associated with beetle trap captures (p = 0.006, ∑wi = 1). Stand and landscape predictors contributed comparably to explaining spatial variation in trap captures. These results indicate that local host composition and fine-scale anthropogenic disturbance are associated with spatial variation in M. alternatus adult activity in mountainous forest landscapes. The identification of 250 m as the spatial scale of strongest landscape association provides a spatially explicit reference for improving surveillance and management strategies for pine wilt disease in topographically complex forest systems.