Biology and Age-Specific Fertility Table of Encarsia pergandiella (Hymenoptera: Aphelinidae) on Bemisia tabaci Nymphs

Abstract

Developmental biology and reproductive performance of Encarsia pergandiella were investigated under controlled laboratory conditions using nymphs of Bemisia tabaci as hosts to evaluate the parasitoid’s potential for biological control programs. Experiments were conducted at constant temperature and relative humidity to determine developmental duration, survivorship, longevity, fecundity, and age-specific fertility parameters of the parasitoid. Female parasitoids successfully parasitized second- and third-instar nymphs of B. tabaci, with higher parasitism rates recorded on younger host stages. The developmental period from egg to adult emergence was completed within a relatively short duration, indicating rapid population growth potential under favorable environmental conditions. Adult females survived significantly longer than males and exhibited higher reproductive activity during the early stages of adult life. Age-specific survival and fecundity schedules demonstrated peak oviposition within the first few days after emergence, followed by gradual decline with increasing age. Life table analysis revealed positive intrinsic rate of increase, high net reproductive rate, and short mean generation time, confirming the capacity of E. pergandiella to establish and multiply efficiently on B. tabaci populations. Host feeding behavior and successful parasitoid emergence contributed to substantial mortality of whitefly nymphs. The results also indicated that environmental stability and host availability strongly influenced reproductive success and survival of the parasitoid. Biological characteristics observed in the present study suggest that E. pergandiella possesses desirable attributes for integration into sustainable whitefly management programs, particularly in greenhouse and protected cultivation systems where B. tabaci outbreaks frequently occur.