Distribution of the African armyworm,Spodoptera exempta(walker) (Lepidoptera: Noctuidae), and the frequency of larval outbreaks in Africa and Arabia

Abstract

AbstractSpodoptera exempta(Walker) occurs very widely in Africa south of the Sahara and in south-western Arabia, and more intermittently in the eastern Indian Ocean and Pacific areas. Throughout its range, the extent and frequency of its attacks have increased markedly, especially in the last 10–15 years. In parts of Africa and in south-western Arabia it is now regularly a seasonally important pest; examples are given of monthly distribution maps of the frequency of its attacks in this region. Maps such as these provide a useful and wide-based perspective for those concerned with prediction, survey and control ofS. exemptain a more limited area and with little or no access to information from other territories. Year to year variations within the general patterns derived from many years' records are illustrated by the distribution of outbreaks in three recent seasons, in all of which there were outbreaks in at least seven countries of central and eastern Africa, in two years in Arabia, and in one year also in southern and western Africa.