Distribution, frequency of attack and seasonal incidence of the African armyworm Spodoptera exempta (Walk.) (Lep.: Noctuidae), with particular reference to Africa and southwestern Arabia.
The distribution of the noctuid Spodoptera exempta in Africa south of the Sahara and in adjacent parts of south-western Arabia is mapped in detail. The author aims to help those concerned with monitoring and controlling the pest by making available the wider historical data needed for anticipating outbreaks. For the pan-African region, the monthly distribution and frequencies of incidence are presented as 12 maps showing the number of years in which infestations have been recorded in each degree-square of latitude and longitude during the period 1940-82. Theories on the occurrence of outbreaks are discussed. For each territory, there is an index to the years and months when outbreaks were recorded, and a summary of the monthly frequencies of occurrence. The incidence and importance of S. exempta in each country are summarized.