Related Experiment Video
Updated: May 18, 2026
Disclosing Hemolymph Collection and Inoculation of Metarhizium Blastospores into Rhipicephalus Microplus Ticks Towards Invertebrate Pathology Studies
Published on: June 1, 2019
First report of fipronil resistance in Rhipicephalus (Boophilus) microplus of Mexico
Robert J Miller1, Consuelo Almazán, Martín Ortíz-Estrada
1USDA, ARS Cattle Fever Tick Research Laboratory, 22675 N. Moorefield Rd., Edinburg, TX 78541, USA. robert.miller@ars.usda.gov
Abstract:
Five strains of Rhipicephalus (Boophilus) microplus collected from Tamaulipas Mexico were tested for resistance against several classes of acaricides commonly used. All were resistant to fipronil. Four of five were co-resistant to permethrin and coumaphos in addition to being resistant to fipronil. One strain, El Zamora was found multi-resistant to permethrin, coumaphos, fipronil, and amitraz. Selection with fipronil for 3 generations produced a resistance ratio of 8.3 and 9.4 at the LC(50) and the LC(99) estimates, respectively. Permethrin resistance in El Zamora was possibly linked to elevated esterase (CZEST9) and could be a contributing factor of resistance to fipronil. The implications of resistance for the control of the southern cattle tick in the future are discussed.
