Stem borers of cereal crops at Kongwa, Tanganyika, 1950-52

Abstract

The annual loss of grain caused by stem borers is probably in the region of 50 per cent in a year of heavy infestation. This loss is brought in three main phases; many seedlings are destroyed, the yielding capacity of the plant is reduced by the material damageto the stem, and extensive lodging may occur just before harvest. Two species of stem borers have been found at Kongwa and it appears likely that the carry-over from season to season is maintained in crop residues remaining after harvest and in volunteer and actively regenerating sorghum.