Eficiência de alguns carrapaticidas comerciais em bovinos artificialmente infestados com o carrapato Boophilus microplus. (Canestrini, 1887)

Were tested live comercials formulation of tickcides, with differents active principies, in 40 dairy heifers, artificially infested with approximatelly 4000 larvaes from 200 mg of eggs, in the -21, -14, -7, -1, +3. +10, +14, +17 and +21 days. The day 0 (zero) was the day of a application of tickcides: 1) Ectomin (Cipermetrine); 2) Grenade (Cialotrin); 3) Ultimate (Alfametrine); 4) Triatox (Amitraz); 5) Bayticol (Flumetrine). The products 2 and 5 were used in “pour on” way, when the others were used in spray application form. The counts of semi-engorged female ticks (4.5 to 8.0 mm long) were done 21 days after infestation and analised as log (count +1). The effect of tickcides in the differents instares wasn’t equal. All of then had excellent effects in ticks with 20 and 14 days of infestation and less efficience in ticks of 7 days of infestation. All the tested products had good residual effect in larvaes that had infested the animais in the day +3. The product 5 (Bayticol) was the one who presents the best residual effect during 7 days, whill the others hadn’t residual effects in this fase.