Biological Parameters and Life Table Statistics of Nabis pseudoferus (Hemiptera: Nabidae) Fed on Spodoptera exigua Eggs

Abstract

The nabid predator Nabis pseudoferus is an important generalist insect predator contributing to the suppression of lepidopteran pests in agroecosystems. Laboratory studies were conducted to evaluate its biological parameters and life table statistics when fed on eggs of Spodoptera exigua under controlled environmental conditions. Developmental duration, survival rate, adult longevity, fecundity, and demographic parameters were assessed to determine the predator’s biological performance and population growth potential. The predator successfully completed its life cycle on S. exigua eggs, demonstrating high adaptability and effective utilization of the prey. Nymphal development progressed through successive instars with relatively high survival rates, particularly under moderate temperature and humidity conditions. Feeding activity increased with developmental stage, with later instars and adult females exhibiting the highest predation rates. Female longevity and fecundity were significantly higher than those of males, with peak oviposition occurring during the early reproductive period followed by gradual decline with age. Life table analysis indicated a positive intrinsic rate of increase, high net reproductive rate, and short mean generation time, reflecting strong population growth potential under prey-rich conditions. Survival curves showed gradual mortality across life stages, with higher survivorship observed in early instars. The demographic performance of N. pseudoferus highlights its potential as an effective biological control agent against S. exigua in vegetable and field crop systems. Continuous prey availability enhanced reproductive output and population establishment. The results emphasize the predator’s strong functional role in regulating lepidopteran egg populations and its suitability for integration into pest management programs.