Boophilus annulatus

Ineffective at 3 mg/kg BW against fever ticks (Boophilus annulatus, B. microlopus) and the American dog tick (Dermacentor variabilis). At 5 mg/kg BW, famphur was effective (87-97%) against fever ticks but ineffective against the dog tick. At the highest daily release rate, famphur was 100% effective against fever ticks between days 12 and 41, but remained ineffective against the dog tick... 

In South America, as in Africa, toxaphene is at present the material of choice for tick control on cattle. Applied as a spray at the 0.25% dosage, toxaphene controls Boophilus annulatus microplus for nearly 4 weeks. Raising the dosage to 0.75% produced no significant increased the duration of control, according to Laake. A mixture containing 0.25% benzene hexachloride and 0.50% DDT was notably less effective than 0.25% toxaphene. 

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