Biological control of Asiatic corn borer (Ostrinia furnacalis Guenee) and corn earworm (Helicoverpa armigera Hubner)
1987
Tandan, J.S. | Nillama, N.C. (Central Mindanao Univ., Musuan, Bukidnon (Philippines). Dept. of Entomology)
The effectivity of applying Bacillus thuringiensis Berliner using Dipel and thuricide insecticide as spray and releasing parasitoids Trichogramma evanescens Westwood in controlling major insect pests of corn were studied during the wet season of 1985 in the Central Mindanao University Experiment Station [Philippines]. The objectives of the study are to (1) determine which of the two microbial insecticides give the best control of corn borer and corn earworms; (2) determine the effectivity of Trichogramma evanescens; (3) find out which of the treatments will give the highest yield; and (4) determine the economic cost and return analysis on the application of microbial insecticides and parasitoids in controlling the pest. Generally, all the treatments showed significant effects in reducing corn borer and corn earworm infestation over the control. The parasitoids (Trichogramma evanescens) was effective in reducing egg stage of corn borer and corn earworm. Dipel insecticide was effective in controlling the larvae of corn borer and corn earworm followed by thuricide insecticide. The application of the parasitoids, Dipel and Thuricide insecticides had no effect on predators and other parasites, instead it increased their number. Based on the actual yield, plot treated with Dipel showed the highest yield/ha followed by Trichogramma, Thuricide and the control. The cost and return analysis confirmed that the parasitoids treatment had lesser expenses compared to Dipel and Thuricide application but the highest net return per pesos was obtained by the Dipel treated plots.
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