Insecticide activity of clove essential oil on bean weevil and maize weevil/Atividade inseticida do oleo essencial de cravo-da-india sobre o caruncho-do-feijao e o gorculho-do-milho

• Published in: Revista brasileira de engenharia agrícola e ambiental 2016-01, Vol.20 (1), p.72
• Main Authors: Jairoce, Carlos F, Teixeira, Cristiano M, Nunes, Camila F.P, Nunes, Adrise M, Pereira, Claudio M.P, Garcia, Flavio R.M
• Format: Article
• Language: Spanish
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v20n1p72-77

Bean weevil and maize weevil can cause considerable damage to stored grains. These insects are mainly controlled with synthetic chemical insecticides, which may bring serious problems to human and environmental health. Therefore, this study aimed to evaluate the efficiency of the essential oil of clove [Syzygium aromaticum (L.) Merrill & Perry (Myrtaceae) (origin: Bahia, season Sep. 2014-Feb.2015)] in the control of S. zeamais and A. obtectus under laboratory conditions. The essential oil was extracted through the classic hydrodistillation process and its chemical components were identified via gas chromatography. Oil efficiency was tested at the doses of 35, 17.9, 8.9, 3.6, 1.8, 0.4 and 0.2 [µ.sup.L] [g.sup.-1] (derived from a pilot study) for insect control and the [LC.sub.50] was determined. The results showed that eugenol was the major compound. The essential oil caused mortality of 100% for both species 48 h after treatment with the concentrations of 17.9 and 35 [µ.sup.L] [g.sup.-1]. The [LC.sup.50] for A. obtectus was 9.45 [µ.sup.L] [g.sup.-1], against 10.15 [µ.sup.L] [g.sup.-1] for S. zeamais. The use of clove essential oil represents a promising alternative to be used under storage conditions for the integrated management of stored grains pests. Key words: control strategies insert infestations grain storage O caruncho-do-feijao e o gorgulho do milho podem causar grandes prejuizos aos graos armazenados. Entre as alternativas de controle esta a utilizacao de oleos essenciais de plantas com propriedades inseticidas; objetivou-se, assim, avaliar a eficiencia do oleo essencial de cravo-da-india no controle de S. zeamais e A. obtectus em condicoes de laboratorio. O oleo essencial foi extraido por processo classico de hidrodestilacao e seus constituintes quimicos foram identificados por cromatografia gasosa. A eficiencia deste oleo foi testada nas doses 35; 17,9; 8,9; 3,6; 1,8; 0,4 e 0,2 [µ.sup.L] [g.sup.-1] (oriundas de um trabalho piloto) no controle dos insetos e determinada a [CL.sub.50]. Os resultados mostraram que o eugenol foi o composto majoritario. O oleo essencial causou 100% de mortalidade para as duas especies 48 h apos o tratamento com as concentracoes de 17,9 e 35 [µ.sup.L] [g.sup.-1]. A [CL.sub.50] para A. obtectus foi 9,45 [µ.sup.L] [g.sup.-1] contra 10,15 [µ.sup.L] [g.sup.-1] do S. zeamais. A utilizacao do oleo essencial de cravo-da-india representa uma alternativa promissora a ser usada em condicoes de armazenagem para o manejo integrad