Effects of Different Levels of Drought Stress in Ficus Plants on the Life History and Population Growth of Perina nuda (Lepidoptera: Lymantriidae): An Age-Stage, Two-Sex Life Table Analysis

Under the background of global climate change, frequent drought events have significantly impacted plant-insect interaction. This study focuses on <i>Ficus microcarpa</i>, an important landscaping and urban greening tree species in tropical and subtropical regions, and its primary herbivorous pest, <i>Perina nuda</i>, by applying the age-stage, two-sex life table theory to systematically evaluate the effects on the life history traits and population dynamics of <i>P. nuda</i> reared on <i>F. microcarpa</i> subjected to different levels of drought stress. The results demonstrated that reared on drought-stressed <i>F. microcarpa</i> significantly altered multiple life history traits of <i>P. nuda</i>. All drought treatments significantly shortened the larval development period. Under both light and severe drought conditions, adult lifespan was prolonged, the total pre-oviposition period was reduced, fecundity per female increased, and generation time (<i>T</i>) was shortened. However, significant increases in pupal weight, intrinsic rate of increase (<i>r</i>), and finite rate of increase (<i>λ</i>) were observed only under light drought stress. The population prediction results indicate that both light and severe drought stress lead to obviously higher population growth rates and larger population sizes at 200 days compared to the control group. These findings suggest that the population fitness of <i>P. nuda</i> is enhanced under light and severe drought stress, potentially increasing the probability of pest outbreaks. This study provides an important theoretical basis and practical advice on forecasting population dynamics and implementing integrated management strategies for <i>P. nuda</i> in the context of climate change.