Submitted to: Journal of Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/5/2006
Publication Date: 6/12/2006
Citation: Nathan, S.S., Mankin, R.W., Kalaivani, K., Murugan, K. 2006. Effects of millet, wheat, rice, and sorghum diets on development of Corcyra cephalonica (Stainton) (Lepidoptera: Galleriidea) and its suitability as a host for Trichogramma chilonis Ishii (Hymenoptera:Trichogrammatidae). Journal of Environmental Entomology. 35:784-789. Interpretive Summary: Rearing and releasing parasitoids is an important pest control technique, but care must be taken to raise the highest quality and lowest cost natural enemies. Scientists in Korea, India, and the Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL have conducted research on development of improved methods for rearing wasps that attack pest insects. The wasps are reared on insect eggs and transported to locations where biological control is used as an integrated pest management tool. Typically, the wasps are mass-produced on eggs of an easily grown stored product insect pest like the rice moth. In this study, it was found that rice moths produced better eggs for wasps when they were reared on millet than when they were reared on rice, wheat, or sorghum. These results can lead to improved efficiency of wasp mass-rearing programs.
Technical Abstract: The growth and reproductive ability of the parasitoid, Trichogramma chilonis (Ishii), was compared in eggs laid by Corcyra cephalonica (Stainton) that had been reared on broken grains of finger millet (Eleusine coracana L. Gaertn), soft white wheat (Triticum aestivum L)., short-grained white rice (Oryza sativa L.) or durra sorghum (Sorghum bicolor [L.] Moench). The percent hatch and percent survival of T. chilonis were significantly higher on C. cephalonica hosts reared on finger millet than those reared on sorghum, possibly because larvae and adults of millet-reared C. cephalonica ranked significantly higher on several measures of development and survival than those reared on sorghum. Percent adult emergence, mean 1st-instar-weight, and the consumption index, relative growth rate, efficiency of conversion of ingested food, and efficiency of conversion of digested food of 5th instars were significantly higher for millet-reared C. cephalonica than for those reared on sorghum. Wheat- and rice-reared C. cephalonica ranked intermediate between millet and sorghum on these development and survival measures. Potential reasons for such differences are discussed. Improved knowledge of the nutritional ecology of the parasitoid and host can lead to improved efficiency of Trichogramma mass rearing programs.