Baccharis dracunculifolia (Asteraceae) essential oil toxicity to Culex quinquefasciatus (Culicidae)

Made available in DSpace on 2019-10-04T12:31:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-11-01 Universidade Federal de Sao Joao Del-Rei (UFSJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The control of mosquitoes by means of chemical insecticides has been a problem, mainly due to the possibility of resistance developed by insects to xenobiotics. For this reason, demand for botanical insecticides has increased. In this sense, the present work aims to verify the susceptibility and morphological and biochemical alterations of Culex quinquefasciatus larvae after exposure to essential oil (EO) of leaves of Baccharis dracunculifolia. To observe the larvicidal action, larvae were exposed to EO at concentrations of 25, 50, 100, and 200 mg/L, until their emergence to adults. The control group was exposed to deionized water and dimethyl sulfoxide. Morphological analyses were also carried out using hematoxylin and eosin, mercury bromophenol blue, Nile blue, and periodic acid Schiff. Biochemical analyses of total glucose, triacylglyceride (TAG), protein, and acetylcholinesterase levels were performed. The phytochemical analysis of the EO showed (E)-nerolidol as the major compound (30.62%). Larvae susceptibility results showed a LC50 of 34.45 mg/L for EO. Morphological analysis showed that there were histological changes in midgut. For biochemical analyses, the glucose level in the larvae exposed to EO for 24 h decreased significantly, unlike the TAG levels, which increased. The total protein level of the larvae also increased after exposure for 24 h, and acetylcholinesterase levels decreased significantly. Taking all our data into account, we can conclude that EO causes destabilization in larva, leading to histological changes, metabolic deregulation and, consequently, their death. Univ Fed Sao Joao del Rei, Campus Ctr Oeste Dona Lindu, Av Sebastiao Goncalves Coelho 400, BR-35501296 Divinopolis, MG, Brazil Univ Estadual Paulista, Dept Biol, Inst Biociencias Rio Claro, Av 24 A,1515 Jardim Vila Bela, BR-13506900 Rio Claro, SP, Brazil Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Cidade Univ Pioneiros, BR-79070900 Campo Grande, MS, Brazil Univ Fed Sao Paulo, Dept Bioquim, R 3 Maio,100 Vila Clementino, BR-04044020 Sao Paulo, SP, Brazil Univ Estadual Paulista, Dept Biol, Inst Biociencias Rio Claro, Av 24 A,1515 Jardim Vila Bela, BR-13506900 Rio Claro, SP, Brazil