The influence of rainfall on the seasonal abundance and flight activity of the maize stalk borer, Busseola fusca in South Africa

This study attempts to demonstrate the extent to which seasonal fluctuations in the number of Busseola fusca (Fuller) moths can be explained by precipitation data. Daily flight activity is shown to be enhanced by cool, humid conditions and restricted by rain. Humidity was shown experimentally to be of importance in the survival of moths under laboratory conditions. It is suspected that the observed relationship between seasonal moth numbers and rainfall is an indirect one and that survival of moths is rather determined by the direct influence of humidity. More serious infestations can therefore be expected during years with favourable rains.