Extratos vegetais obtidos de espécies nativas do Cerrado brasileiro no controle do ácaro-rajado (Tetranychus urticae Koch)
Data
2017-08-08
Autores
Agustini, José Antonio [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O ácaro rajado, Tetranychus urticae Koch, é uma praga que ataca várias culturas em todo o mundo. Seu controle é feito basicamente por acaricidas químicos sintéticos. O uso inadequado de defensivos agrícolas, além de acarretar problemas ao meio ambiente, ao trabalhador e ao consumidor, pode levar ao desenvolvimento de populações de pragas resistentes aos seus princípios ativos. Extratos vegetais têm sido estudados na busca de novos princípios ativos que causem menos problemas ambientais, ocupacionais e de saúde humana, e que possam fazer parte de programa de manejo integrado de pragas e doenças. As florestas brasileiras são constituídas por uma grande diversidade de plantas que podem apresentar metabólitos secundários interessantes com propriedades biocidas. O objetivo deste estudo foi avaliar extratos aquosos e hidroetanólicos de folhas e cascas de doze espécies vegetais nativas do Cerrado brasileiro quanto à atividade acaricida e ao efeito sobre a fecundidade de fêmeas do ácaro-rajado, T. urticae. De cada espécie vegetal foram avaliados dois órgãos (folhas e cascas), duas épocas de coletas (primavera/verão e outono/inverno) além de dois tipos de solventes (água e etanol 70%). Os extratos foram aplicados por pulverização em torre de Potter, avaliando-se mortalidade, repelência e oviposição após 120 horas. Todas as doze espécies apresentaram atividade acaricida significativa sobre T. urticae, dependendo da época de coleta, do material vegetal e do solvente utilizado. Em nove espécies houve pelo menos um tratamento em algum dos experimentos com a soma de mortalidade e repelência superior a 80%. Em dez espécies houve pelo menos um tratamento em algum dos experimentos com mortalidade superior a 70%. Três espécies, Xilopia aromatica, Kielmeyera variabilis e Qualea parviflora, causaram mortalidades superiores a 70% em algum tratamento nas duas épocas de coleta. O extrato hidroetanólico de folhas de K. variabilis resultou em soma de mortalidade e repelência superior a 68% nos quatro experimentos. O extrato aquoso de folhas de Q. parviflora resultou em mortalidade superiores a 69% em todos os quatro experimentos. Essas três espécies apresentam potencial como biocida vegetal no controle de T. urticae.
The two-spotted spider mite, Tetranychus urticae Koch, is a pest that attacks various crops throughout the world. The mites control is basically made by synthetic chemical acaricides. The inappropriate use of pesticides, besides causing problems to the environment, to the workers and the consumers, can lead to the development of populations of pests resistant to its active ingredient. Some pesticides such as neonicotinoids and pyrethroids have their origin in secondary plant metabolites such as tobacco and chrysanthemum, respectively. Plant extracts have been studied in the search for new active ingredients that cause less environmental, occupacional and human health problems, and that can be part of an integrated pest and disease management program. The Brazilian forests are constituted by a great plant diversity that can have interesting secondary metabolites with biocide properties. The objective of this study was to evaluate the mitecide activity of the aqueous and hydroethanolic extracts of leaves and bark of twelve native species from the Brazilian Cerrado and their effect on the fecundity of T. urticae mite females. Two plant organs (leaves and barks), two collection seasons (spring/summer and autumn/winter) were evaluated from each plant species, besides two types of solvents (70% ethanol and water). The extracts were applied by Potter tower spray, evaluating mortality, repellency and oviposition after 120 hours. All twelve species showed significant miticide activity on T. urticae, depending on the collection period, the plant material and the solvent used. In nine species there was at least one treatment, in any of the experiments, with the sum of mortality and repellency higher than 80%. In ten species there was at least one treatment in one of the experiments with mortality higher than 70%. Three species, Xilopia aromatica, Kielmeyera variabilis and Qualea parviflora, caused mortality higher than 70% in some treatments in the two collection seasons. The hydroethanolic leaf extract from K. variabilis resulted in the sum of mortality and repellency higher than 68% in all four experiments. The aqueous extract of leaves of Q. parviflora resulted in mite mortality higher than 69% in the four experiments. These three species have potential as plant biocide for controlling T. urticae.
The two-spotted spider mite, Tetranychus urticae Koch, is a pest that attacks various crops throughout the world. The mites control is basically made by synthetic chemical acaricides. The inappropriate use of pesticides, besides causing problems to the environment, to the workers and the consumers, can lead to the development of populations of pests resistant to its active ingredient. Some pesticides such as neonicotinoids and pyrethroids have their origin in secondary plant metabolites such as tobacco and chrysanthemum, respectively. Plant extracts have been studied in the search for new active ingredients that cause less environmental, occupacional and human health problems, and that can be part of an integrated pest and disease management program. The Brazilian forests are constituted by a great plant diversity that can have interesting secondary metabolites with biocide properties. The objective of this study was to evaluate the mitecide activity of the aqueous and hydroethanolic extracts of leaves and bark of twelve native species from the Brazilian Cerrado and their effect on the fecundity of T. urticae mite females. Two plant organs (leaves and barks), two collection seasons (spring/summer and autumn/winter) were evaluated from each plant species, besides two types of solvents (70% ethanol and water). The extracts were applied by Potter tower spray, evaluating mortality, repellency and oviposition after 120 hours. All twelve species showed significant miticide activity on T. urticae, depending on the collection period, the plant material and the solvent used. In nine species there was at least one treatment, in any of the experiments, with the sum of mortality and repellency higher than 80%. In ten species there was at least one treatment in one of the experiments with mortality higher than 70%. Three species, Xilopia aromatica, Kielmeyera variabilis and Qualea parviflora, caused mortality higher than 70% in some treatments in the two collection seasons. The hydroethanolic leaf extract from K. variabilis resulted in the sum of mortality and repellency higher than 68% in all four experiments. The aqueous extract of leaves of Q. parviflora resulted in mite mortality higher than 69% in the four experiments. These three species have potential as plant biocide for controlling T. urticae.
Descrição
Palavras-chave
Extrato aquoso, Extrato hidroetanólico, Kielmeyera variabilis, Biocidas, Controle natural, Aqueous extract, Hydroethanolic extract, Biocides, Natural control, Qualea parviflora