Relative competitiveness for progeny production in Trichogramma chilonis versus Trichogramma japonicum on Corcyra cephalonica eggs

Mass reared trichogrammatid egg parasitoid species are deployed globally for augmentative biocontrol of many lepidopteran crop pests. In India, Trichogramma chilonis Ishii is being recommended for release against of many caterpillar pests, while T. japonicum with longer ovipositor is advocated against yellow stem borer in rice or top borer in sugarcane to reach the eggs which are covered by the moth scales. When these two Trichogrammatid species either co- occur in crop ecosystems or are released simultaneously in the same target crop , their relative progeny production will depend both on their innate fecundity and also the competitive ability of the females to parasitise the available host eggs in the same niche. In the first laboratory study, mated females of two species-T.chilonis and T.japonicum were kept, both alone (6:0 and 0:6) and together in ratios of 3:3, 5:1, 1:5, for oviposition on equal numbers of eggs of the factitious host, Corcyra cephalonica.. The progeny produced had more numbers of T.chilonis than T.japonicum across most ratios. The two species were which case the progeny production was greater when T.chilonis was allowed access first instead of T.japonicum first. successive, which confirmed that T.japonicum as both less fecund and less competitive for progeny production with Trichogramma chilonis.