Acaricide potential of Xylopia emarginata Mart. leaf extract against Rhipicephalus microplus larvae | Potencial acaricida do extrato de folhas de Xylopia emarginata Mart. contra larvas de Rhipicephalus microplus

English. The objective of this work was to evaluate the in vitro carrapaticidal action of ethanol extract (EE) of Xylopia emarginata leaves Mart.com different tannin contents on R. microplus larvae. For this, as leaves of X. emarginata were collected monthly during the period of 12 months to evaluate the production of tannins through the solveylysis technique catalyzed by butanol/HCl. To evaluate the efficacy of EE, the larvae bundle test (TPL) was performed with reading in the interval of 24 hours of incubation using concentrations of 25 to 100 mg mL-1, the negative control containing distilled water and the positive control containing chemical carrapaticide. It was observed that the EE containing 5.9% tannin content promoted 80.44% mortality at the concentration of 100 mg mL-1. The EE containing 13.2% tannin content promoted 97.43% mortality at 100 mg mL-1. Thus, high larvicidal activity of ethanol extracts of leaves of X. emarginata on Larvae of R. microplus was verified and this activity may be related to tannin contents.

Portuguese. O objetivo desse trabalho foi avaliar a ação carrapaticida in vitro do extrato etanólico (EE) de folhas de Xylopia emarginata Mart. com diferentes teores de taninos sobre larvas de R. microplus. Para isso, as folhas de X. emarginata foram coletas mensalmente durante o período de 12 meses para avaliar a produção de taninos através da técnica de solvólise catalisada por butanol/HCl. Para avaliar a eficácia do EE, foi realizado o teste do pacote de larvas (TPL) com leitura no intervalo de 24 horas de incubação utilizando as concentrações de 25 a 100 mg mL-1, o controle  negativo contendo água destilada e o controle positivo contendo carrapaticida químico. Observou-se que o EE contendo 5,9% de teor de taninos promoveu 80,44% de mortalidade na concentração de 100 mg mL-1. O EE contendo 13,2% de teor de taninos promoveu 97,43% de mortalidade a 100 mg mL-1. Dessa forma, constatou-se alta atividade larvicida dos extratos etanólicos de folhas de X. emarginata sobre larvas de R. microplus e essa atividade pode estar relacionada aos teores de taninos.