Three years work at Mtwapa Research Station summarises the fluctuation of Chilo spp. and Sesamia spp. Chilo partellus has been been shown to be just as important as C. orichalcociliellus nearer the coast, but Sesamia calamistis becomes important towards the second growing season.
The loss caused by these borers to maize plants in the field has been estimated to be high when no chemical treatment is applied, but such a loss varies with the intensity of infestation. Control of the borers by cultural methods relies on planting maize at the onset of rains. Selected chemical treatment at the appropriate time reduces the loss by about 20%.
