Submitted to: Memoirs of the American Entomological Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 5, 2000
Publication Date: N/A
Interpretive Summary: Cutworm moths in the family Noctuidae are major agricultural pests causing billions of dollars of damage annually. The genus Spodoptera, known as armyworms, is the most destructive group of Noctuidae in terms of monetary loss to agriculture worldwide. There has been no comprehensive revisonary study of armyworms on a world level. Species limits were uncertain and relationships were unknown; thus, distributions, larval host plants, and potential economic importance for species could not be accurately determined. In this first large scale study, 30 species are recognized, and the distribution, larval host plants, parasitoids, predators are cited for each. Adults of all 30 species and larvae of 20 species are described. Keys and illustrations are provided for accurate identification of both adults and larvae. Fifteen of the 30 species are considered pests of agricultural products on a world level. This phylogeny provides insight on nthe relationships among pest and non-pest species that may spawn new research in the fields of biological control, feeding preference studies, and physiological experiments. The results of this study will be important to scientists, ecologists, economic entomologists, biological control workers, farmers, and insect physiologists. APHIS-PPQ inspectors and identifiers will find this an important quide to prevent entry of agricultural pests into the United States.
Technical Abstract: The world fauna of the armyworm genus Spodoptera Guenee is revised. A phylogeny of Spodoptera is constructed based on cladistic relationships of the 30 species. Two genera that are sister groups of Spodoptera based on a molecular phylogeny of the Noctuidae serve as outgroups. The data set contains 39 morphological characters (5 binary and 34 multistate) comprised dof 190 character states. Cladistic analysis uses the parimony program Hennig86 produced two trees with a length of 304, a consistency index of 0.49, and a retention index of 0.74. Seven monophyletic clades containing 2 to 5 species are recognized. Four species are not part of any of the seven clades, but are sister taxa to larger monophyletic groups on the trees. These are S. exiguum which is the most plesiomorphic species, S. dolichos and S. androgeum are sister species to the littoralis, cosmiodes, and pulchellum clades (including S. frugiperda), and S. frugiperda is the sister species of the cosmiodes and pulchellum clades. Descriptions, distributions, and illustrations of all adults and 30 species of larvae are included. Keys are provided to adults based on color pattern and morphology. Five new synonyms are proposed and 13 lectotypes are designated. A specimen database is prepared for material examined. Databases are produced for larval host plants, parasitoids, predators, and a bibliography to the records contained in these databases.