Abstract
This study examines host plant use and larval performance in Actias ningpoana ningtaiwana (Taiwanese Chinese moon moth) across ten native and cultivated tree species in Taiwan. Larval performance was assessed by measuring growth rate, developmental time, and survival across instars under controlled feeding trials. Results revealed significant interspecific variation in host suitability. Larvae developed most rapidly and successfully on Liquidambar formosana, while Pyracantha koidzumii and Lagerstroemia speciosa failed to support early instar survival. A negative correlation between developmental duration and survival suggests that faster development may enhance larval fitness. We propose the Bankruptcy at the End of Month hypothesis to describe a recurring pattern of delayed mortality observed in some host treatments. Under this framework, larvae experiencing suboptimal nutrition may survive early and middle instars, yet encounter physiological failure in the final instar due to cumulative resource deficits. Although the phenomenon of late-stage mortality from early nutritional limitations is recognized in insect ecology, this hypothesis provides a heuristic model to describe such patterns in an ecologically relevant context. It emphasizes that early-stage survival does not necessarily predict overall developmental success, particularly in variable or marginal host environments. These findings contribute to a deeper understanding of host plant suitability, larval resource allocation, and developmental bottlenecks in herbivorous insects, with practical implications for forest management and plant-insect interaction studies.