Impact of Solar Radiation, Rainfall and Cannibalism on Disappearance of Maize Stemborers in Kenya

The effect of solar radiation, rainfall and cannibalism on the disappearance of eggs and larvae of the cereal stemborer Chilo pattellas (Swinhoe) were studied. Disappearance and nonviability of egg batches was higher on plants exposed to solar radiation than on shaded plants. Significantly fewer small larvae were recovered from plants exposed to rainfall than from shielded plants. Cannibalism among larvae of the same size was not common except at high larval densities. Contrary to the common belief that disappearance is the result of predation, these studies show that solar radiation and rainfall might also play an important role in the disappearance of stemborer eggs and small larvae.