# 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

## TL;DR

This study shows how drought stress affects the life cycle and population growth of a pest species, Perina nuda, feeding on Ficus plants, with implications for pest management under climate change.

## Contribution

The study introduces a novel application of age-stage, two-sex life table analysis to assess the impact of drought stress on a pest species.

## Key findings

- Light drought stress maximizes the fitness of Perina nuda, enhancing development, reproduction, and population growth.
- Severe drought stress also increases population growth rates and sizes compared to the control group.
- Drought stress alters key life history traits, including larval development time and adult lifespan.

## Abstract

Based on the age-stage, two-sex life table theory, this study systematically investigated the effects of reared on Ficus microcarpa subjected to different levels of drought stress on the life history traits and population dynamics of Perina nuda. The research findings demonstrate that the effects of different levels of drought stress on P. nuda exhibit a nonlinear pattern. Under light drought stress, the fitness of this pest reaches its peak, manifested by optimal levels across key parameters including development, reproduction, and population growth. In contrast, moderate drought stress had a relatively weak effect; while severe drought stress promoted some life history parameters, its overall impact was weaker than that of light drought stress. The population prediction results indicate that both the growth rate and population size of P. nuda under light and severe drought stress are obviously higher than the control group. These findings suggested that light and severe drought stress enhanced the suitability of F. microcarpa as a host plant, thereby potentially increasing the risk of pest outbreaks. This study provides a critical scientific foundation for predicting population dynamics and implementing ecological management strategies for P. nuda in the context of climate warming.

Under the background of global climate change, frequent drought events have significantly impacted plant–insect interaction. This study focuses on Ficus microcarpa, an important landscaping and urban greening tree species in tropical and subtropical regions, and its primary herbivorous pest, Perina nuda, by applying the age-stage, two-sex life table theory to systematically evaluate the effects on the life history traits and population dynamics of P. nuda reared on F. microcarpa subjected to different levels of drought stress. The results demonstrated that reared on drought-stressed F. microcarpa significantly altered multiple life history traits of P. nuda. 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 (T) was shortened. However, significant increases in pupal weight, intrinsic rate of increase (r), and finite rate of increase (λ) 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 P. nuda 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 P. nuda in the context of climate change.