Atividade acaricida in vitro de plantas medicinais da caatinga do Nordeste Brasileiro sobre teleóginas de Rhipicephalus (Boophilus) microplus (CANESTRINI, 1887) (Acari: Ixodidae).

Abstract

The objective of this study was to evaluate the in vitro acaricide efficiency of ethanolic extracts from Croton blanchetianus Baill (marmeleiro), Jatropha mollissima (Pohl) Baill (pinhão bravo) and Hyptis suaveolens (L.) Poit. (alfazema brava) comparing them with some used commercial acaricides on biological parameters of Rhipicephalus (Boophilus) microplus (CANESTRINI, 1887) (Acari: Ixodidae). Engorged ticks were collected from naturally infested cattle attended in Veterinary Hospital from Universidade Federal de Campina Grande (UFCG) Campus Patos. These animals received no treatment for acaricide for at least 50 days prior to collection of ticks. Females of R. (B.) microplus were placed in plastic containers and immediately taken to the Laboratório Multiusuário de Pesquisas Ambientais (LAMPA) where it went to in vitro experimentation consisting on the immersion tests of engorged females. It were prepared from each plant three solutions to give concentrations of 5%, 10% and 25%. Six control groups were prepared, one containing distilled water (negative control), the other containing 96% ethanol and four groups using commercial acaricides diluted in distilled water in the manner proposed by the manufacturer, the latter being, deltametrina 25%, cipermetrina 15%, amitraz 12,5% and an association of ethion 60% and cipermetrina 8% (positive controls). All treatments were made at triplicate. Were evaluated the percentage of oviposition reduction (RO), the hatching rate reduction (RE) and the percentage of control (PC). The extracts of all the plants in the 25% concentration showed acaricidal efficacy in vitro, similar to amitraz group, the best result between the chemical insecticide groups. The control groups with distilled water and ethanol did not differ, assuming that the acaricide action is due, probably, to the compounds present in plants evaluated.