Effect of Ephestia elutella diets on fitness of the third trophic level, the parasitoid Habrobracon hebetor (Hymenoptera: Braconidae)

In the three-level nutritional structure of plant–phytophagous insect–natural enemies, plants exert direct and indirect effects on natural enemies. Additionally, the effect of the host diet on natural enemies also has an indirect impact on pest control. Herein, the effects of two diets of Ephestia elutella on the fitness of its natural enemy Habrobracon hebetor were studied using an age–stage, two-sex life table analysis. The results indicated that the total fecundity, the number of eggs laid during each oviposition day (Ed), oviposition days, and female longevity of the H. hebetor of F0 generation parasitized on E. elutella fed an artificial diet were significantly higher than those on E. elutella fed tobacco leaves. The pre-adult survival, paralysis, and parasitism rates of the H. hebetor F1 generation parasitized on E. elutella fed an artificial diet were also significantly higher than those on E. elutella fed tobacco leaves. The results provide a theoretical basis for the large-scale propagation of H. hebetor in the laboratory and for improving the efficiency of H. hebetor in controlling E. elutella in tobacco warehouses.