Abstract:The beet armyworm, Spodoptera exigua (Hübner), is a polyphagous pest with worldwide distribution in tropical and subtropical regions. A number of investigations have demonstrated that this species is a strong migrant, and in temperate areas, the initiation of outbreaks by immigrants has been well documented. In recent years, the beet armyworm has risen to the status of an economically important pest of many kinds of crop in China. It has become a problem especially in the north of the country, even though t...