Armyworms are the caterpillars of some members of two genera:
Many Spodoptera including: African armyworm (Spodoptera exempta) (Africa) Fall armyworm (Spodoptera frugiperda) (North and South America) Lawn armyworm (Spodoptera mauritia) Some Mythimna (moth) including: Common armyworm or true armyworm (Mythimna unipuncta) (North and South America) Northern armyworm, Oriental armyworm or rice ear-cutting caterpillar (Mythimna separata) (Asia)