RESUMO
A newly broad spectrum parasiticide, Ivermectin, and two old acaricides [Coumaphose and malathion] were in field application trials against, Boophilus annulatus ticks, naturally infested animals in an endemic area. The use of combinations between both [old and recent ones] were studied and also the economical aspects of their application taken in consideration. Ivomec s/c injection gave the best clearance rate [96.4%] for adults ticks and 94.3% for nymphal stages] with the longest protection period [35 days] but it was the highest price and the most time consuming and manipulation difficulties. Coumaphose showed moderate clearance rate [85.9% for adult ticks and 89.1%] for nymphal stages and moderate protection period [6 days]. While, malathion was the lowest clearance rate [68.4% for adult ticks and 68.6 for nymphal stages] and protection period [4 days]. Combination of half dose Ivomec injection and half dose Coumaphose spray more effective than combination between half dose Ivomec and half dose Malathion, but more expensive with low integrity. While combinations of half dose of Ivomec and full dose of Coumaphose more reliable with high effectiveness and long protection and period but more expensive