Manejo de Coleópteros-praga de feijão armazenado com óleos essenciais

Abstract

With a big grain yield of beans in Brazil, proper storage is crucial to prevent pest attack. The main pests that attack stored beans noteworthy Zabrotes subfasciatus Boh and Callosobruchus maculatus (Fabr.) (Coleoptera, Chrysomelidae, Bruchinae), which develop within the grain causing direct and indirect damage. In this sense, the present work aimed to evaluate the use of essential oils for the control of these coleopteran pests of stored beans and verify the effects of these oils on seed vigor of cowpea. Oils of Croton heliotropiifolius Kunth, Croton pulegiodorus Baill., M. urundeuva Allemão extracted in the laboratory, and Ocimum basilicum L., purchased business company were used. Tests to evaluate the fumigant effect, repellent and residual oils on the two pests and tests on the germination of bean were performed. To C. maculatus observed that only the oil via spraying O. basilicum caused 100% mortality. In relation to the oil repellent effect C. pulegiodorus and O. basilicum showed only minor dosage classified as neutral and the other repellents, and these oils stood causing high mortality and therefore, fewer eggs and adults emerged. To be was observed that Z. subfasciatus oils of C. pulegiodorus and O. basilicum caused 100 % mortality via fumigation and were classified as repellent at all doses. To the residual effect was highlighted oil C. pulegiodorus. In germination experiments oil M. urundeuva in lower doses (5 μL) obtained the highest percentage of emerged plants (18, 75%), no significant differences for the other oils being observed. Also no significant differences for the variables index of germination speed, speed of emergence and emergence rate coefficient were observed. We conclude that the essential oils used do not affect the seed germination of beans, regardless of dosage, and C. pulegiodorus and O. basilicum are promising for the control of bruchid Z. subfasciatus and C. maculatus.