Host Selection of the Spherical Mealybug (Homoptera: Pseudococcidae) by Anagyrus indicus (Hymenoptera: Encyrtidae): Influence of Host Stage on Parasitoid Oviposition, Development, Sex Ratio, and Survival

Abstract

The gregarious encyrtid parasitoid, Anagyrus indicus , oviposits in all three nymphal stages and in the adult female stage of the spherical mealybug, Nipaecoccus vastator . In no-choice tests, the frequency of hosts parasitized, and the number of eggs deposited per host were significantly greater in third nymphal and adult female mealybugs than in either first- or second-stage nymphs. In choice tests, significantly more adult females were parasitized than third-stage nymphs, and the first and second nymphal stages were not parasitized. A. indicus was able to complete development and emerge following parasitism of each of the four host stages, but parasitoid development was the fastest, the number of parasitoids emerging was the greatest, and the ratio of female to male parasitoids was the highest following oviposition in third nymphal and adult female hosts. Our findings have implications for mass-rearing and field colonization of A. indicus and provide support for recent predictive models of reproductive strategies in parasitic Hymenoptera.