Conventional and alternative insecticides, including a granular formulation of Bacillus thuringiensis var. kurstaki for the control of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) in Kenya

Abstract

The microbial insecticide, Bacillus thuringiensis Berliner var. kurstaki (Dipel 10G), was effective against larvae of the maize stalk borer, Busseola fusca (Fuller), in two separate trials in Kitale, Kenya during the 1987 growing season. In the first trial, B. thuringiensis applied at different times, was compared against DDT (5% dust), endosulfan (Thiodan 3G), trichlorphon (Dipterex 2.5G), ash, diatomaceous earth, and an untreated control. The level of suppression provided by the later B. thuringiensis treatments was equivalent to DDT and trichlorphon but inferior to endosulfan. Ash and diatomaceous earth treatments proved ineffective. In the second trial, destructive sampling of B. thuringiensis‐treated plots and untreated control plots was used to assess B. thuringiensis's Impact on the nature and degree of stalk borer infestation. Four developmental categories were assigned to larvae of various head capsule widths and pupae comprised a fifth category. Significantly (P < 0.05) fewer individuals of all but the first developmental category were found in the plants treated with B. thuringiensis. Results suggest that B. thuringiensis may have residual activity against B. fusca larvae for at least 3½ weeks after application when applied directly in whorls.

Keywords:

• Busseola fusca
• Bacillus thuringiensis var. kurstaki
• pesticides
• Kenya
• microbial control