Submitted to: Journal of Agricultural and Urban Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2000
Publication Date: 1/18/2000
Citation: Yoshida, M., Shanower, T.G. 2000. Helicoverpa armigera larval growth inhibition in artificial diet containing freeze-dried pigeonpea pod powder. Journal of Agricultural and Urban Entomology. 17(1): 37-41. Interpretive Summary: Pigeonpea is an important crop in the semi-arid regions of Asia and Africa. It is heavily damaged by Helicoverpa armigera, and despite extensive and exhaustive efforts, no resistant cultivars have been identified from the pigeonpea germplasm. A related, wild species has been reported to be resistant to this insect pest. We compared the growth and survival of H. armigera larvae reared on artificial diets containing freeze-dried pod powder from pigeonpea, the related wild species, and an untreated control. We found that pods of both pigeonpea and the wild species inhibited larval growth as compared to the control. The compounds that caused this effect were extractible in acetone and 70% methanol. Extraction of pigeonpea pods with ethyl acetate also produced growth inhibition. This results are important because they begin to identify compounds that may confer resistance to this pest. Further work is needed to isolate and identify the compounds.
Technical Abstract: Helicoverpa armigera is the most important pest of pigeonpea, Cajanus cajan. A related wild species, Cajanus scarabaeoides, is reported to be resistant. In this study we compared the growth and development of H. armigera on artificial diets containing freeze-dried pod powder from pigeonpea, C. scarabaeoides, and an untreated control. Diets containing both pigeonpea and C. scarabaeoides pod powder inhibited larval growth and survival. The compounds responsible for this effect were extracted in acetone and 70% methanol. In addition, ethyl acetate extracts of pigeonpea pod powder also produced growth inhibition. The compounds producing these effects were not identified. The importance and relevance of these findings to current research efforts is also discussed.