Resistência de variedades de feijão crioulo Vigna unguiculata (L.) Walp. do estado de Alagoas ao ataque de Callosobruchus maculatus (Fabr., 1775) (Coleoptera: Chrysomelidae, Bruchinae)

Abstract

In Brazil, cowpea Vigna unguiculata (L.) Walp. represents one of the primary sources of food and income for rural populations, especially in the North and Northeast regions. In these areas, the cultivation of traditional (landrace) cowpea varieties has been increasingly recovered and promoted within family-based, Indigenous, and quilombola farming systems. However, growers face the persistent challenge of phytophagous insect infestations, with particular emphasis on the bruchid beetle Callosobruchus maculatus (Fabricius, 1775), a key pest of stored cowpea grains. Therefore, this study aimed to evaluate host preference and the developmental performance of C. maculatus on three landrace varieties of V. unguiculata collected in the semi-arid highlands of Alagoas state. For host preference assays under choice conditions, 20 g of each landrace variety were paired and exposed to 10 unsexed C. maculatus adults. Under no-choice conditions, the following biological parameters of C. maculatus were assessed: number of emerged adults, viable eggs, and unviable eggs. The landrace variety Aracê was the least preferred by C. maculatus in comparison to the landraces Manteiga and Riso do Ano, as well as the commercial variety Macassar, after 24 hours of exposure. Regarding the biological performance parameters, the Riso do Ano landrace exhibited the highest mean numbers of emerged adults, viable eggs, and unviable eggs, significantly differing from the other varieties. These findings suggest both antixenosis (non-preference) and antibiosis (adverse biological effects) resistance mechanisms in the Aracê landrace among the varieties analyzed in this study.