Host stage preference, functional response and biological parameters of Aphelinus asychis walker on Myzus persicae (sulzer) in bell pepper

The parasitoid, Aphelinus asychis Walker (Aphelinidae: Hymenoptera), is an important naturally occurring solitary koinobiont endo-parasitoid of green peach aphid, Myzus persicae (Sulzer) (Aphididae: Hemiptera). To supplement the augmentative or conservation biological control of M. persicae in capsicum, the host stage preference, functional response, and biological parameters of this parasitoid on M. persicae was studied. The parasitoid was able to parasitize all the nymphal stages of the aphid with preference to the second instar (51%) followed by the first instar (46%). The biological parameters of the A. asychis viz. total development, pre-oviposition, oviposition, post-oviposition periods, sex ratio (F: M), and fecundity were 16.23±0.45, 1±0.00, 6.6±0.40, 1.6±0.40 days, 1:0.97, and 58.8 eggs female⁻¹, respectively. The parasitoid when offered with different densities viz. 10, 15, 20, 25, and 30 of the second instar nymphs of M. persicae exhibited a Type-II functional response. Theoretically, parasitoid could parasitize a pinnacle of 18.25 aphids within 24 h. The present study indicates that the parasitoid has a potential for supplementing the augmentative and/or conservation biocontrol of the pest. The study also underscores the scope of optimizing the second instar nymphs of the aphid for mass production of the parasitoid.