Influence of Host Stage on Oviposition, Development, Sex Ratio, and Survival ofAnagyrus kamaliMoursi (Hymenoptera: Encyrtidae), a Parasitoid of the Hibiscus Mealybug,Maconellicoccus hirsutusGreen (Homoptera: Pseudococcidae)

Abstract

Host stage selection, host suitability, and sex allocation by the solitary encyrtid parasitoid, Anagyrus kamali Moursi (Hym., Encyrtidae), were studied in laboratory experiments in order to improve mass production of this parasitoid. All nymphal stages and adult females of the Hibiscus Mealybug (HMB), Maconellicoccus hirsutus Green (Hom., Pseudococcidae), were parasitized in no-choice experiments. In two-choice experiments third larval instar and preoviposition adult females were the most preferred, in terms of number of hosts selected for oviposition. The number of eggs per host was consistently greater in adult females than in nymphal stages. However, in adult female mealybugs, more than 60% of the parasitoid’s eggs were encapsulated. More parasitoid progeny emerged from younger host stages than from older ones; nevertheless, the A. kamali sex ratio from hosts which were parasitized as early instars was close to one. Parasitized third instars and adult female mealybugs produced a population of A. kamali with a sex ratio of 0.4. Our findings have implications for mass rearing of the parasitoids, since the parasitoid choice of the host stage in which it oviposits strongly influences the production of female progeny. r 1999 Academic Press