Preferência do pulgão-preto, Aphis craccivora Koch, a diferentes genótipos de feijão-de-corda, Vigna unguiculata (L.) Walp

This research was conducted with the intention of evaluating the response of different cowpea, Vigna unguiculata (L.) Walp, cultivars to the black aphid (Aphis craccivora Koch). The bioassays were conducted from August through October of 2004 in a greenhouse at the Ceara Federal University (UFC) campus. The cowpea cultivars used were: Epace-10, Epace-11, Patativa, Pingo de Ouro, Pitiuba, BR-10 Piaui, BR-12 Caninde, BR-14 Mulato and BR-17 Gurgueia. Each assay had five treatments and six replications in a completely randomized block design. The genotypes were raised in a 300ml plastic cup and maintained in cages protected by an insect proof net. Plants were infested twelve days after planting with five adult females per plant. Evaluations were performed three and five days after infestation by visual counting of the adults and nymph forms present on the plants. A variance and Tukey analysis were done with the obtained data at a 5% level of probability. The Epace 10 and Patativa cultivars were less preferred by A. craccivora.