Migration Flight by an Aphid, Rhopalosiphum Maidis (Hemiptera: Aphididae), and a Noctuid, Spodoptera Frugiperda (Lepidoptera: Noctuidae)

An instance of medium-range migration by Rhopalosiphum maidis (Fitch) and of long-range migration by Spodoptera frugiperda (J. E. Smith) are documented and the weather systems that made the migrations possible are detailed. Although both species were carried beyond their northern limit for overwinter survival and little damage ensued, the usefulness of synoptic weather analysis in explaining sudden population increases is shown.