Insecticide Resistance and Tolerance in the Brown Dog Tick

Brown dog ticks (Rhipicephalus sanguineus) are the only North American tick species that can maintain infestations indoors and are notoriously difficult to control once established. A research team, led by Dr. Amanda Eiden of the University of Florida, recently published a research paper that explored the problem by analyzing levels of acaricide resistance and tolerance in field populations of the brown dog tick. Ticks from kennels and residential facilities that had experienced acaricide failures in Florida and Texas were obtained and ticks were screened for resistance and tolerance to permethrin and fipronil, two actives commonly used to control brown dog ticks. All 9 populations screened for permethrin resistance were found to be resistant or highly resistant while populations analyzed for fipronil resistance were found to be tolerant but not resistant.