Resistance of Cowpea Genotypes to Zabrotes subfasciatus (Boheman, 1833) (Coleoptera: Chrysomelidae: Bruchinae)

Abstract

<p class="4Body"><span lang="EN-US">Cowpea (<em>Vigna unguiculata</em> (L.) Walp.) when stored is mainly attacked by bruchid Coleopterans. The control of these pests is done primarily through chemicals, however, with problems related to the selection of resistant insects, alternative forms of control are searched. Seeking an alternative control, the objective this work was to evaluate the resistance of cowpea genotypes to the attack of <em>Z. subfasciatus</em>. In the first selection of genotypes were evaluated 35 cowpea genotypes, being observed the variables: number of eggs, number of insects emerged and weight loss (%). In this first selection of cowpea were selected 10 genotypes. In the second selection of genotypes, the 10 most resistant from the first selection were used, but with eight repetitions per genotype, besides evaluating the egg viability (%) and instantaneous rate of population growth. The cowpea genotypes showed significant differences for resistance to attack by <em>Z. subfasciatus</em>. The most resistant to <em>Z. subfasciatus</em> were BRS Tracuateua, 31 MNC03-720C-20, 26 MNC00-553D-8-1-2-2 and 37 MNC05-832B-234-5.</span></p><p> </p

Resistance of important bean genotypes to the Mexican bean beetle [Zabrotes subfasciatus (Bohemann)] during storage and its control with chemical synthetic and botanical insecticides

“…Despite this fact, Z. subfasciatus is recognized as being one of the few Bruchids able to feed on a variety of beans, including those belonging to the genera Phaseolus (common beans), Vigna (cowpea) (Sales et al, 2005;Bifano et al, 2010) and Vicia (broad beans) (Pacheco and Paula, 1995;Toledo et al, 2013). Differences in resistance of bean species to Z. subfasciatus have been well documented and are attributed to many causes, including the presence of trypsin and proteinase inhibitors, lecithins and tannins, all of which are deleterious to the development of Z. subfasciatus (Osborn et al, 1986;Posso et al, 1992;Pereira et al, 1995;Guzmán-Maldonado et al, 1996;Acosta-Gallegos et al, 1998;Barbosa et al, 2000;Aguiar et al, 2006;Moraes et al, 2011).…”