Detection of Permethrin Resistance and Fipronil Tolerance in Rhipicephalus sanguineus (Acari: Ixodidae) in the United States

Abstract

Permethrin is a commonly used acaricide for tick control on domestic animals and in residential environments, while fipronil use is restricted to on-animal treatment. Following widespread reports of permethrin and fipronil application failures to control indoor infestations of Rhipicephalus sanguineus (Latreille), the brown dog tick, 31 tick populations were obtained from Florida and Texas for acaricide resistance screening. These field-collected ticks from kennels and residential facilities were challenged with technical grade permethrin and fipronil to create dose response curves that were compared with an acaricide-susceptible strain. Permethrin resistance was successfully screened in nine populations, all of which were resistant or highly resistant. Tick susceptibility to fipronil was conducted on four populations, which were found to be tolerant, with resistance ratios below 10. This is the first documentation of R. sanguineus permethrin resistance and fipronil tolerance in the United States. Potential causes of resistance development and recommendations on future brown dog tick control management plans are discussed.

Identification of permethrin and etofenprox cross‐tolerance in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae)

“…Laboratory reared, permethrin susceptible and presumably etofenprox susceptible R. sanguineus s.l. (Ecto Services Inc., Henderson, NC) (hereafter referred to as the susceptible colony) were used in a bioassay to determine the etofenprox DC for this species.…”

“…The generated LC 99 was subsequently evaluated against the susceptible colonies obtained from the Centers for Disease Control and Prevention and Oklahoma State University. Thereafter, the LC 99 value was doubled to establish the DC . The permethrin DC value, 0.19% active ingredient (AI), was established by Eiden et al …”

“…Thereafter, the LC 99 value was doubled to establish the DC . The permethrin DC value, 0.19% active ingredient (AI), was established by Eiden et al …”

“…(Latreille; Acari: Ixodidae) is distributed worldwide and is a vector of numerous pathogens to dogs and occasionally humans across its range . Several studies have reported that this tick is capable of developing resistance to multiple acaricide classes . Resistance to synthetic pyrethroids (SPs), organophosphates (OPs), and the formamidine amitraz, have been reported in Europe, and North America .…”

Tick-Borne Zoonoses in the United States: Persistent and Emerging Threats to Human Health

“…Brown dog ticks spend most of their life span off of their hosts, concealed in cracks and crevices of walls in kennels, homes, and other peridomestic harborages. Because of the cryptic behavior and small size of larvae and nymphs, low-level peridomestic infestations can escape attention, allowing populations to increase rapidly (Eiden et al 2015). The duration of the brown dog tick life cycle is temperature dependent, but under favorable conditions, Rh.…”