Cellular and metabolic response of hemolymph from engorged Rhipicephalus microplus females exposed to fluazuron

Abstract

The aim of the present study was to evaluate the hemolymph of engorged females of Rhipicephalus microplus ticks exposed to the growth regulator fluazuron. Firstly, the engorged females were divided into two groups (control and treated) and these were subjected to an immersion test. Hemolymph was collected 24 and 48 hours after the immersion test, to evaluate the cellular and metabolic response. In comparison with the control group, the treated group had lower total hemocyte counts at both times, with lower granulocyte counts and higher spherulocyte counts. There were reductions in glucose and total protein values in both the control and the treated group at the 48-hour evaluation, compared with the 24-hour evaluation. There were no changes in activity levels of lactate dehydrogenase and aspartate aminotransferase enzymes in either group at both times. Fluazuron was not able to promote changes in the energy metabolism of the ticks under the conditions established for this study, but this growth regulator proved to be capable of promoting changes in hemocyte dynamics.

Keywords

• hemolymph, tick, ectoparasiticide, growth regulator.