African Journal of Biotechnology Vol. 2 (11), pp. 425-428, November 2003

ISSN 1684-5315  © 2003 Academic Journals

Full Length Research Paper

Comparative efficacy of microbial and chemical insecticides on four major lepidopterous pests of cotton and their (insect) natural enemies

T. A. Fadare* and N. A. Amusa

Institute of Agricultural Research and Training, Obafemi Awolowo University, P.M.B. 5029, Moor Plantation, Ibadan, Nigeria.

*Corresponding author. E-mail: naamusa@softhome.net.

Accepted 23 October 2003

Three microbial (biotrol, dipel and thuricide) and three chemical insecticides (monocrotophos, endosulfan and carbaryl) were compared for efficacy on four major lepidopterans and their natural enemies in replicated field trials at Moor Plantation, Ibadan. Thuricide was evaluated at different combinations with monocrotophos in a second trial. The results showed that the microbials caused the mortalities of destructive bollworms and leafroller but allowed the survival of their natural enemies. The chemicals on the other hand caused mortalities of both destructive and useful species. Both groups of insecticides enhanced seed cotton yields. Application of thuricide followed by monocrotophos was better than other combinations evaluated.

Key words: microbial insecticides, Bacillus thuringiensis, cotton.