Invivo and Invitro Acaricide Efficacy Evaluation on Cattle Ticks in Selected Areas of Wolaita and Dawuro Zones, Ethiopia

Abstract

This study was conducted from June, 2013 to May, 2014 in selected areas of Wolaita and Dawuro zones, with the core intentions of to assess the type and efficacy of the most frequently used acaricides in the areas, to identify the most prevalent cattle tick species and recommend the effective acaricide for cattle tick control. To achieve these objectives preliminary survey; invitro and invivo acaricide efficacy evaluation techniques have been conducted. The major tick species identified in order of their importance were Rhip(Boophilus) decoloratus (60.92%), Amblyomma variegatum (28.26%), A.cohaerens (7.82%) and A.gemma (3.0%). Diazinon 60%EC, Amitraz 12.5%, Ivermectin and Deltamethrin, according to their importance, was the acaricides frequently used in the areas. For the invitro technique, a total of 320 Rhip(Booph) decoloratus and 320 A.variegatum engorged adult female ticks were collected from each study sites and the standard modified adult immersion test (AIT) was employed for two successive round. On the other side of study, the efficacies of all the four acaricides at dose of concentration recommended by the manufacturer were assessed all the way through purposively selecting a total of 255 naturally tick infested cattle aged between 1 to 5 years. The invitro result indicates as most of Rhip(Booph) decoloratus dipped in Diazinon at 0.06% solution laid eggs and in this case about 59.92% control achieved. Conversely, only a few Rhip(Booph) decoloratus ticks dipped in Deltamethrin (%C=93.03%) and Amitraz 0.025% (%C=89.08%) had laid eggs. Amblyomma variegatum immersed in Amitraz 0.025% (%C=94.51%) and Deltamethrin (%C=94.06%) had laid small batches of eggs. In contrast, almost all of the ticks in the control group (water treated) have successfully laid eggs. The overall mean oviposition response inhibition of both Amitraz 0.025% and Deltamethrin solution were higher than Diazinon 0.06% and it have shown statistically significant (P<0.05) variation. Diazinon 0.06% has also shown significantly fewer efficacies (79.79%C) than all the three drugs (Amitraz 0.025%=99.89%C, Deltamethrin 1%=99.22%C and Ivermectin 1ml/50Kg=99.14%C) in removing the adult ticks at field level assessment. Therefore, it can be recommended that, for effective cattle tick control in the area, threshold tick control approaches using most effective acaricide Amitraz, Deltamethrin and Ivermectin when tick infestation exceeds an acceptable level.

Keywords: Acaricides, Cattle, Efficacy evaluation, Invivo and Invitro, Ticks