Antibiosis levels to Spodoptera frugiperda (Lepidoptera: Noctuidae) in cowpea commercial cultivars and landrace varieties.
Spodoptera frugiperda (J.E. Smith) is a major pest of cowpea, (Vigna unguiculata [L] Walp.) (Fabales: Fabaceae), and to date, few tactics are available to control this pest. This study was conducted to evaluate whether cowpea commercial cultivars and landrace varieties express antibiosis to S. frugiperda. The commercial cultivars were developed by the Brazilian Agricultural Research Corporation (Embrapa), and the landrace varieties were obtained from indigenous communities of Mato Grosso do Sul, Brazil. The effects of the cowpea genotypes (commercial cultivars and landrace varieties) were assessed on the development, survival, and reproductive capacity of the insect. Out of six genotypes, the two landraces were the most resistant to the pest. Landrace Juti decreased larval weight and survival, and no larvae reached the pupal phase. Landrace Nioaque adversely affected the larval and pupal weight, the period of development from larva to pupa, adult emergence, and the period of development from larva to adult. The cultivar Fradinho was classified as moderately resistant for reducing the larval and pupal weights, and delaying the period of development from larva to pupa. The cultivar Miranda was susceptible regarding the growth and survival of S. frugiperda, however, females reared on this cultivar laid a lower number of eggs. The resistant genotypes, especially the landrace varieties are promising for future plant breeding programs, with the objective of developing resistant cultivars to S. frugiperda larvae.