Suitability of three Lepidopteran host species for mass-rearing the egg parasitoid Trichogrammatoidea eldanae Viggiani (Hymenoptera: Trichogrammatidae) for biological control of cereal stemborers

Abstract

Trichogrammatoidea eldanae Viggiani (Hymenoptera: Trichogrammatidae) is an egg parasitoid of several lepidopteran insect pests in West Africa. In this study, we assessed the suitability of three different host species viz; Eldana saccharina Walker (Lepidoptera: Pyralidae), Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) as potential host for mass-rearing T. eldanae. This was done by determining the biological parameters of the parasitoid on the different host species. The effect of rearing host species on the performance of T. eldanae was also investigated. The parasitoid successfully developed on all tested host species. However, the biological parameters including fecundity, number of adults emerged per parasitised egg, progeny and developmental period varied significantly with host species. The number of parasitised eggs and the progeny per female were highest on Corcyra cephalonica (80 ± 10.72 and 103.66 ± 13.44, respectively) and there was no significant difference between E. saccharina (35.44 ± 7.11 and 38.44 ± 9.01, respectively) and S. calamistis (32.33 ± 5.94 and 57.33 ± 10.02, respectively). The shortest developmental period (9.17 ± 0.026) was recorded on C. cephalonica and the longest on E. saccharina (9.20 ± 0.051). The highest intrinsic rate of increase (0.37 ± 0.02) was recorded on C. cephalonica and the lowest (0.32 ± 0.01) was recorded on E. saccharina. Moreover, the host species used to rear T. eldanae did not affect its reproductive potential. It resulted from this study that C. cephalonica was the most suitable host and can be used to mass-rear T. eldanae for augmentative purpose to control cereal stemborers.