Life History Parameters and Age-Specific Mortality of Spodoptera littoralis (Lepidoptera: Noctuidae) on Beet

Abstract

Life history parameters and age-specific mortality of Spodoptera littoralis (Lepidoptera: Noctuidae) were evaluated on beet crops to understand its developmental performance, survival dynamics, and population growth potential under controlled laboratory conditions. Observations included developmental duration of immature stages, survivorship, fecundity, and stage-specific mortality across successive generations reared on beet foliage. Results indicated successful completion of the life cycle, with relatively short developmental time and high larval survival, demonstrating strong host suitability of beet for larval growth and development. Adult longevity and fecundity varied significantly between sexes, with females exhibiting higher reproductive output and longer oviposition periods. Life table analysis revealed favorable demographic parameters, including high intrinsic rate of increase, net reproductive rate, and finite rate of increase, indicating strong population expansion potential under optimal environmental conditions. Age-specific mortality patterns showed higher survival during early larval stages, while increased mortality was observed during late larval and pupal stages, likely due to physiological stress and developmental constraints. Temperature and host plant quality significantly influenced developmental rate and survival, with optimal performance recorded under moderately warm conditions. Continuous availability of beet foliage supported sustained larval feeding and enhanced population growth. The study highlights the pest potential of S. littoralis on beet and underscores its capacity for rapid population buildup in agroecosystems. These findings provide essential baseline data for developing predictive models and integrated pest management strategies aimed at minimizing crop damage through timely monitoring and targeted control measures.