PLANTÐINSECT INTERACTIONS Effects of Millet, Wheat, Rice, and Sorghum Diets on Development of Corcyra cephalonica (Stainton) (Lepidoptera: Galleriidae) and Its Suitability as a Host for Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae)

Emergence and survival of adults for 24 hwas compared forTrichogramma chilonis Ishii reared on eggs of Corcyra cephalonica (Stainton) adults whose larval growth and development had beenmonitored on broken grains of four different cereals: Þngermillet (Eleusine coracanaL.Gaertn), softwhitewheat (TriticumaestivumL), short-grainedwhite rice (Oryza sativaL.), anddurra sorghum (Sorghum bicolor L. Moench). For C. cephalonica, the percentage adult emergence and several Þfth-instar food use indices (consumption index, relative growth rate, and efÞciencies of conversion of ingested and digested food) were signiÞcantly higher for millet-reared than for sorghum-reared larvae. The nutritional indices for wheatand rice-reared C. cephalonica larvae were intermediate between the indices for larvae reared on millet and sorghum. The percentage adult emergence and percentage 24-h survival of T. chiloniswere signiÞcantly higher on eggs of C. cephalonica hosts reared on millet than on eggs of those reared on sorghum. These results suggest that the rearing of C. cephalonica larvae on a high-quality nutritional source resulted in high-quality eggs, which ultimately resulted in high-quality T. chilonis reared on those eggs. Such an effect has been modeled in ecological theory as a “bottom up cascade.” Improved knowledge of the nutritional ecology of parasitoids and hosts can lead to improved understanding of the ecological mechanisms affecting host plant, host, and parasitoid abundance, as well as to improved efÞciency and quality of Trichogramma production in mass rearing programs.