Alternate Host Plants of Cowpea Curculio, (Coleoptera: Curculionidae) in Alabama

Abstract

Cowpea curculio, Chalcodermus aeneus (Boheman), is an important pest of cowpea, Vigna unguiculata (L.) Walpers, in the southeastern United States. This insect also feeds on other fabaceous crops and a number of wild host plants. In a field survey done in Alabama during 1992 to 1994, adults of cowpea curculio were collected on 31 alternate host plant species representing 11 plant families, and eggs and larvae were collected on three fabaceous plant species of the subtribe Phaseolinae. Before the cowpea cropping season in the spring, some of the alternate host plants of adults included narrow-leaved vetch, Vicia sativa ssp. nigra (L.) Erhardt, purple cudweed, Gnaphalium purpureum L., heartwing sorrel, Rumex hastatulus L., cutleaf eveningprimrose, Oenothera laciniata L., and moss verbena, Verbena tenuisecta Briquet. In May and June, cowpea curculios reproduced on snapbean pods, Phaseolus vulgaris L., before cowpea plants bloomed, indicating that adults from this new generation could infest cowpeas during pod formation. Adults fed on sicklepod, Senna obtusifolia (L.) Irwin & Barneby, during the cowpea cropping season. After the end of the cowpea cropping season, cowpea curculio produced an overwintering generation on Strophostyles umbellata (L.) Elliott and S. helvula (Muhlenburg ex Willdenow) Britton. Adults overwintered in clumps of broomsedge, Andropogon virginicus L. Purple cudweed, heartwing sorrel, moss verbena, and sicklepod may represent new host records for cowpea curculio. Destruction of spring alternate hosts and overwintering hosts of cowpea curculio and crop rotation of cowpeas away from snapbeans may help to reduce cowpea curculio infestation in cowpea.