[In Vitro efficacy of comercial formulations of ixocidides in engorged female of Boophilus microplus collected of dairy cattle at Paraíba Valey in the state of São Paulo].

Laboratory trials were realized between the year 2001 at 2004 to evaluate the efficacy of commercial ixodicides against samples of Boophilus microplus collected of dairy bovines in 17 properties of eight cities at Paraíba Valey region, State of São Paulo Brazil. The trials was performed against engorged female using immersion technique. It was evidenced low efficacy of products of the chemical groups synthetic pyrethroid (28.24%) and amitraz (47.19%). The best efficacy was presented by products of the association between synthetic pyrethroid with organophosphorus (88.64%).