Comparative in Vitro Study on the Efficacy of Some Commercial Insecticides against Rhipicephalus (Boophilus) annulatus Ticks

Abstract

Commercially available preparations including Butox® 50% (containing 5% deltamethrin), Diazinon 15% and Achook 0.15% (containing 0.15% Azadirachtin) were compared for their acaricidal activity against Rhipicephalus (Boophilus) annulatus engorged females obtained from naturally infested cattle from Rashid city, Behera Province, Egypt, and other developmental stages using immersion test. It was found that the highest mortality (86.6%) was achieved by using Diazinon 15% and Achook at concentrations of 4 ml/l and 0.15%, respectively. The complete inhibition of oviposition was observed when using Butox® 50% and diazinon 15% at all used dilutions while Achook caused drop in reproductive index (RI) of tested females reached 75% at concentration of 0.075%. On the other hand, the bioassays on eggs and larvae revealed the superior effect of Achook over Butox® 50% and Diazinon 15%; as the lowest hatchability (0%) of eggs and highest mortality (100%) within the first 24 hours post treatment on unfed larvae was achieved in Achook at both concentrations of 0.15% and 0.075% azadirachtin. Finally, it was concluded that Butox® 50%, Diazinon 15% and Achook 0.15% commercially available pesticides showed variation in percentages of adult tick and larval mortalities, inhibition of oviposition and hatching of laid eggs. Promising results of Achook which is a product for agricultural use and does not have recommended dose for veterinary application yet needs further investigations to be recommended.