ABSTRACT
The aim of this work was to study the influence of essential oil fractionation on acaricidal activity against the cattle tick Rhipicephalus (Boophilus) microplus. The citronella (Cymbopogon winterianus J.) and pepper tree (Schinus molle L.) essential oils were fractionated by vacuum distillation yielding fractions that were analyzed by the GC/MS. Laboratory tests were carried out to determine the effect of the total essential oil and fractions on larvae of the cattle tick R. (B.) microplus. The fractions 04 and 05 of the C. winterianus essential oil were the most active showing LC50 values of 1.20 and 1.34 μL/mL, respectively. The LC50 of the total oil was 3.30 μL/mL while the effect of the fractions 01, 02 and 03 was less pronounced, with LC50 values of 4.37, 4.24 and 3.49 μL/mL, respectively. The fraction 03 of the S. molle essential oil was the most active showing LC50 value of 8.80 μL/mL while the fractions 01 and 02 did not show toxic effects on the larvae.
ABSTRACT
O objetivo deste trabalho foi identificar as espécies de carrapatos que parasitam os cães da área urbana de Porto Alegre e conhecer suas prevalências nesta população. Para isso, foram examinados 450 cães de rua de Porto Alegre, colhidos os carrapatos nos animais infestados e estes identificados ao estereomicroscópio por espécie e por estágio. Dentre os animais examinados, 52,44 por cento albergavam carrapatos e destes, 93,22 por cento estavam parasitados por Rhipicephalus sanguineus, 2,97 por cento por Amblyomma aureolatum e 3,81 por cento pelas duas espécies simultaneamente. Do total de carrapatos colhidos, a espécie mais abundante nos animais foi R. sanguineus representando 99,43 por cento desse total; foram encontrados ínstares de todos os estágios parasitários de R. sanguineus e só do estágio adulto de A.aureolatum.
The purpose of this study was to identify and to know the prevalence of ticks recovered from dogs of urban area of Porto Alegre, RS. Four hundred and fifty stray dogs were examined and the ticks found were identified according to the species and parasitic stage. A percentage of 52.44 percent of those dogs were infested with ticks, among these, 93.22 percent were parasitized by Rhipicephalus sanguineus, 2.97 percent by Amblyomma aureolatum and 3.81 percent by both species. R. sanguineus was the more prevalent species among infested animals representing 99.43 percent of the total number of ticks sampled. All parasitic stages of R. sanguineus were present on the stray dogs but only the adult stage of A. aureolatum was found.