Efficacy of deltamethrin, diazinon, and ivermectin on Boophilus annulatus ticks (in vitro and in vivo study).

Tick infection is considered a cause of major concern as it is a vector for some disease transmission. The use of chemicals to control tick infection is increasing in farm systems. The efficacy of three chemicals was studied on the tick Boophilus annulatus. In vitro and in vivo studies were done. The active ticks were collected from naturally infected cattle for in vitro study. They were incubated with the three chemicals which are commercially used. An in vitro study recorded that the highest effect of the three chemicals was 100% at 3 h postexposure (p.e.) time for deltamethrin and 6 h for diazinon and ivermectin on the adult ticks. Egg batches were less affected. In vivo results showed more plain efficacy. The efficacy of deltamethrin was increased gradually until complete cessation of ticks showed within 3rd day posttreatment (d.p.t.), 100% efficacy. But the tick population begins to reappear gradually within 7 d.p.t., while diazinon showed 100% efficacy at 7 d.p.t. and the ticks reappear again within 14 d.p.t. The most preferred results were obtained with ivermectin which showed 100% efficacy at 7 d.p.t., and the cattle was still free from infection until 21 d.p.t. only. Ticks begin to reappear within 28 d.p.t. in slight few numbers. This concluded that the powerful and safe chemical which is commercially used was ivermectin. Even so, it is used also as an anthelmintic drug.