Sensitivity profile of Rhipicephalus (Boophilus) microplus ticks of dairy cattle to acaricides in small farms in the northwestern São Paulo State, Brazil

摘要: Rhipicephalus (Boophilus) microplus tick is one of the most important parasite afflicting cattle, mainly in taurine breed. Chemical application still widely used way control, although there are reports resisting to many active principles different countries. The goal this study was obtain vitro sensitivity profile dairy cattle ticks six commercial acaricides five small farms northwestern Sao Paulo state, located Bady Bassitt and Ipigua municipalities, investigate productive characteristics control methods applied these farms. R. (B.) engorged females were collected from naturally infested subjected adult immersion test using following drugs: amitraz, cypermethrin, deltamethrin, chlorpyrifos/cypermethrin mix, dichlorvos/cypermethrin dichlorvos/chlorpyrifos mix. In each farm, a questionnaire also administered. Considering mean efficacy level all farms, no product with appropriate level. Pyrethroids had worst results (cypermethrin deltamethrin having 17% 27% respectively), resistance observed Conversely, amitraz (73%), (79%), chlorpyrifos/dichlorvos (76%) exhibited highest efficacies. resistant formulations two herds. farmers not aware tests that detect susceptibility did adopt proper technical procedure when chemicals. These indicate need educate on considering as choice criterion. A constant monitoring relevant. Further investigations region should be conducted better understand levels.