Trichogrammatoidea bactrae (Nagaraja) has been identified as a potential egg parasitoid for managing rice leaf folder (Cnaphalocrocis medinalis) in rice (Oryza sativa L.). Different sugars, i.e. saturated solutions of glucose, fructose, sucrose, undiluted bee honey and distilled water were evaluated as diets for the adult parasitoids in terms of adult longevity. There was a significant variation of longevity among the adults fed with different feed sources. Parasitoids fed with undiluted honey lived the longest (7.2 ± 0.3 days). Subsequently, bee honey at different concentrations, i.e. 100, 50, 33, 25, 20 and 17% was evaluated in terms of adult longevity. The highest longevity of 7.9 ± 0.2 days was found when parasitoid adults were fed with 50% bee honey while the lowest longevity was 1.5 ± 0.2 days on distilled water. Several standard sugar feeding methods were also evaluated in terms of longevity. Honey feeding by filter paper method was the most suited compared to other methods i.e. honey drop, sponge and wick methods. With respect to fecundity, the rate of oviposition with adult age was examined. There was a significant variation of daily oviposition with age. One-day-old parasitoids laid 31.2 ± 3.27 eggs per female with 56.05% of total fecundity, and the laying was reduced to 0.4 eggs per female in five days old parasitoids. The mean fecundity was 55.7 ± 0.26 eggs per female. Effect of rearing of parasitoids on alternate hosts (Corcyra cephalonica) on oviposition was significant. There was a general trend of loosing the ability of parasitism with continuous rearing of progeny on alternative host.
Tropical Agricultural Research Vol. 25 (4): 602 – 609 (2014)