PREVALENCE OF CATTLE TICKS AND ACARICIDE EFFICACY TEST IN ARBA MINCH AREAS IN SOUTHWEST, ETHIOPIA

Abstract

Ticks are responsible for blood loss, tick worry, damage to hides, skins and the injection of toxins and transmit a number of pathogenic organisms of animals than any other arthropod vector group. The relevant information on tick species composition and prevalence, and acaricide efficacy are essential to assess tick infestation and to identify the appropriate measure of tick control. Hence, the objective of this study was to assess the prevalence of cattle tick, species composition and evaluate the efficacy of diazinon and amitraz against cattle ticks in Arba Minch areas, southwest Ethiopia. A cross-sectional study was conducted to assess the prevalence and species composition of cattle ticks in Chano village from May to June 2016, whereas the field acaricide efficacy trial was conducted in Shelle Mella village in September 2016. 404 cattle above one-year-old were sampled randomly in Chano village. Ticks were collected and identified into species. The susceptibility status of ticks to diazinon and amitraz was tested in the laboratory. 120 healthy cattle with higher tick infestation were included for diazinon and amitraz efficacy trial. The baseline tick count was done to randomize into control and intervention groups. Thirty cattle were sprayed by diazinon, thirty by amitraz and remaining sixty were used as control (30 for each acaricide). Tick count was done at day-1, day-2, day-3, day-7, day-14 and day-21 of post treatment. Of the 404 cattle examined, 343 were infested at least by one tick and hence, the prevalence was 84.9%. Four genera and nine species of ticks (Amblyomma variegatum, A. cohaerens, A. lepidum, Hyalomma marginatum rufipes, Boophilus decoloratus, Rhipicephalus pravus, R. praetexatus, R. pulchelus and R. evertsi-evertsi) were documented. A. variegatum was the most prevalent species (71.4%; N = 245), followed by A. cohaerens (6.7%; N = 23). Amitraz and diazinon resulted significant reduction in mean tick count in the field compared to the control. The reduction in tick number due the amitraz was significant up to day- 21 post treatment (P = 0.012), while it was up to 14-day for diazinon (P = 0.03). The acaricidal efficacy of amitraz was superior over diazinon as it showed the maximum percentage reduction and had long residual efficacy. Ticks were susceptible to amitraz and diazinon and hence use of the two acaricides is still promising, but may require repeated application.