In vitro efficacy of diazinon and amitraz on Boophilus decoloratus tick at Sebeta Awas district, Ethiopia

Abstract

This study was conducted in Oromiya region, western Shewa Zone, at Sebeta Awas district, Ethiopia to determine the in vitro efficacy of Amitraz 12.5% and Diazinon 60% against Boophilus decoloratus using adult immersion test. A total of 180 engorged adult female ticks of B.decoloratus were collected from local cattle under extensively managed herds and immersed in Amitraz 12.5% and Diazinon 60% at field recommended concentration and in distilled water for control groups for 1 minute and then incubated at 27 ± 1°C and relative humidity of 85% for 7 days. The oviposition response of B. decoloratus in both groups were observed at regular interval. The mean mass of eggs laid by B. decoloratus of the treated group and those of untreated groups was compared to estimate the efficacy of each tested acaricide. Thus, B. decoloratus treated with Diazinon 60% at field recommended concentration died and did not lay eggs while some of B. decoloratus which were treated with Amitraz 12.5% at field recommended concentration survived and as a result eggs were found in seven days incubation time. There was a statistically significant variation (p <0.05) between the two acaricides in the overall oviposition control of B. decoloratus tick species. On the other hand those treated with water as a control group were able to survive and lay many eggs. Diazinon 60% at field recommended concentration was better in overall mean percent control (C%=100) than Amitraz 12.5% (C%=98.27) of B. decoloratus at field recommended concentration. The results of the study suggested that both Amitraz and Diazinon provide higher oviposition inhibition on B. decoloratus tick. Further study in relation with the in vivo trial is recommended.

Keywords: Acaricides; Boophilus decoloratus; Efficacy; In vitro testing