Repellency and bioactivity of Caatinga biome plant powders against Callosobruchus maculatus (Coleoptera: Chrysomelidae: Bruchinae)

Abstract

The Caatinga biome represents the 4th-largest area covered by single vegetation in Brazil and contains dry forests rich in aromatic bushes, vines, herbs, and trees. The flora of this ecological region is widely known and employed in folk medicine and has other utilitarian and econom- ic uses; however, its potential for controlling or repelling insects is poorly investigated. In this study, we evaluated the potential use of Caatinga plant species for controlling infestations of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae: Bruchinae), the most important insect pest of cowpea, Vigna unguiculata (L.) Walp. (Fabales: Fabaceae). Powders of the leaves and stems of 9 plant species, including Amburana cearensis A. C. Smith (“cumaru”) (Fabales: Fabaceae), Croton sonderianus Müll. Arg. (“marmeleiro”) (Malpighiales: Euphorbiaceae), Cleome spinosa Jacq. (“mussambê”) (Capparales: Cleomaceae), Mimosa tenuiflora Benth. (“jurema-preta”) (Fabales: Fabaceae), Anadenanthera mac- rocarpa (Benth.) Brenan (“angico-vermelho”) (Fabales: Fabaceae), Aspidosperma pyrifolium Mart. (“pereiro”) (Gentianales: Apocynaceae), Senna occidentalis (L.) H.S. Irwin & R.C. Barneby (“manjerioba”) (Fabales: Fabaceae), Hyptis suaveolens (L.) Poit. (“alfazema-brava”) (Lamiales: Lamiaceae), and Ziziphus joazeiro Mart. (“juazeiro”) (Rosales: Rhamnaceae), were applied on masses of cowpea seeds, and their effects on C. maculatus longevity as well as their repellent activities were evaluated. All the leaf and stem powders reduced only the longevity of males and showed strongly repellent activities against females. The preference level of females for untreated beans varied between 73 and 94%, indicat- ing that all the leaf and stem powders can be a part of the integrated management of C. maculatus in storage facilities.