Comparative in vitro Acaricidal Efficacy Evaluation of Amitraz and Diazinon against Ixodid Ticks from Mekelle Dairy Farms, North Ethiopia

The experiment was conducted from June, 2017 to November, 2017 with the objectives of evaluating the acaricidal efficacy of Amitraz and Diazinon emulsion concentrates against ixodid ticks collected from Mekelle dairy farms and assessing the community's perceptions on the practice of acaricide utilization methods. The modified adult immersion test was the experimental protocol carried for the evaluation. Out of 150 adult female engorged ixodid ticks the prevalence of Boophilus decoloratus was 45.5%, Ambylomma lepidum 40% and Ambylomma variegatum 14.5%. Results of the adult immersion test on engorged female ticks have revealed that, Amitraz at 12.5% concentration have produced a significantly higher (P<0.05) level of oviposition inhibition with a percent control of 94.75% in B. decoloratus and A. lepidum than Diazinon at 60% emulsion concentrate (percent control= 80.81%). However, both acaricides were found to be relatively less efficient against B. decoloratus and A. lepidum. Furthermore, in the study area Amitraz and Diazinon were the two mostly used acaricides and acaricide treatment was the only method practiced to control ticks. The practices of manual spraying of the acaricides were found to relay on frequent applications of often inadequate acaricide concentrations without alternation of acaricidal products. In general, under laboratory condition, 12.5% of Amitraz mix seems to provide more oviposition inhibition effect against B. decoloratus and A. lepidum than 60% emulsion concentrate of Diazinon. Hence, in order to assess the residual effect of these acaricides in vivo experimental trial is strongly suggested for future studies.