Aspectos biológicos e de sensibilidade a acaricidas do Dermacentor nitens (Neumann,1897) em eqüinos e muares de alguns municípios de Minas Gerais e de Guanambi, Bahia

Abstract

Several experiments were carried out to study biological aspects of nonparasitic stages of Dermacentcr nitens and the ixodid fauna within the equine ear. Comparisons between populations of D. nitens from the ears and those from the nasal diverticulum of equines from different counties of Minas Gerais and Guanambi, Bahia were made. Biological aspects of D. nitens populations of equines and mules were compared. The susceptibility of D. nitens engorged females from those counties to organophosphorus, pyrethroid and organophosphorus + pyrethroid acaricides was evaluated. Preoviposition, oviposition and incubation periods were similar among the different strains studied. Three species of ticks, D. nitens, Bbophilus microplus and Amblyomma cajennense were found within equine ears. D. njtens was the most prevalent and numerous species followed by B. microplus and A. cajennense. D. nitens was found in the nasal diverticulum simultaneously and independently of ear infestations. Mules were less infested by D. nitens than equines. Differences in susceptibility to organophosphorus acaricide were found among D. nitens females from different counties. Except the Montalvânia/Varzelândia strain, all others strains were susceptibles to pyrethroid acaricide. All strains were similarly susceptibles to organophosphorus + pyrethroid acaricide.