Biology and Reproductive Parameters of Metaphycus flavus (Hymenoptera: Encyrtidae) on Coccus hesperidum

Abstract

Biological attributes and reproductive performance of Metaphycus flavus (Hymenoptera: Encyrtidae) were studied on Coccus hesperidum to evaluate its potential as a biological control agent under controlled laboratory conditions. Developmental duration, survivorship, adult longevity, sex ratio, and fecundity were recorded across successive generations of the parasitoid reared on host colonies maintained on host plant twigs. Results indicated successful completion of development from egg to adult within a single host, with relatively high immature survival and stable emergence rates under optimal temperature and humidity conditions. Female parasitoids exhibited significantly higher longevity and oviposition potential compared to males, contributing to effective population buildup. Reproductive parameters showed a favorable net reproductive rate and intrinsic rate of increase, indicating strong population growth potential when utilizing C. hesperidum as a host. Parasitism efficiency increased with host density up to an optimal threshold, beyond which intraspecific competition and host limitation reduced overall parasitization success. Observations of host feeding and superparasitism were also recorded at higher host densities, influencing parasitoid fitness and progeny quality. The sex ratio was female-biased, enhancing the biological control potential of the species under mass-rearing conditions. Environmental factors such as temperature significantly influenced developmental time and reproductive output, with improved performance observed under moderately warm conditions typical of protected cultivation systems. The study highlights the suitability of M. flavus for augmentative biological control programs targeting soft scale insects in horticultural systems. These findings provide essential baseline information for the development of mass-rearing protocols and field release strategies aimed at integrated pest management in perennial crop ecosystems.