Evidence of acaricide resistance in different life stages of Amblyomma mixtum and Rhipicephalus microplus (Acari: Ixodidae) collected from the same farm in the state of Veracruz, Mexico

Authors: SOUZA HIGA, LEANDRO - Universidade Federal Do Mato Grosso Do Sul; BARRADAS PINA, FRANCISCO - Universidade Federal Do Mato Grosso Do Sul; RODRIGUES, VINICIUS - Universidade Federal Do Mato Grosso Do Sul; VALERIO GARCIA, MARCOS - Universidade Federal Do Mato Grosso Do Sul; ROMERO SALAS, DORA - University Of Veracruzana; Miller, Robert; Perez De Leon, Adalberto - Beto; CAVALCANTE BARROS, JACQUELINE - Embrapa; ANDREOTTI, RENATO - Embrapa

Submitted to: Preventive Veterinary Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2019
Publication Date: 1/1/2020
Citation: Souza Higa, L., Barradas Pina, F., Rodrigues, V., Valerio Garcia, M., Romero Salas, D., Miller, R., Perez De Leon, A.A., Cavalcante Barros, J., Andreotti, R. 2020. Evidence of acaricide resistance in different life stages of Amblyomma mixtum and Rhipicephalus microplus (Acari: Ixodidae) collected from the same farm in the state of Veracruz, Mexico. Preventive Veterinary Medicine. https://doi.org/10.1016/j.prevetmed.2019.104837.
DOI: https://doi.org/10.1016/j.prevetmed.2019.104837

Interpretive Summary: Ticks infesting the same cattle in a farm in the state of Veracruz in Mexico were collected to test their susceptibility to acaricides used for their control. Acaricide resistance makes these ticks difficult to control leading to enhanced tick-borne disease transmission and poor animal health. The ticks collected were different requiring either one-host, in the case of Rhipicephalus microplus also known as the southern cattle fever tick, or three-hosts, in the case of Amblyomma mixtum, to complete their life cycle. Susceptibility testing was done using various acaricide products commercially available to cattle producers in Mexico. Evidence of resistance to amitraz and pyrethroids was detected in both tick species. Products containing acaricide combinations were efficacious against the two tick species con-infesting cattle. This information was transferred to cattle producers in efforts to manage acaricide resistance applying integrated tick management.

Technical Abstract: The objectives of this study were to evaluate the resistance of Amblyomma mixtum and Rhipicephalus microplus ticks from co-infested bovines from the Veracruz region in Mexico to different acaricide families and to demonstrate the viability of the packet test on different A. mixtum instars. The following acaricide families were used: a combination (cypermethrin 15'g'+'chlorpyrifos 25'g'+'citronella 1'g'+'butoxide piperonyl 15'g), amidine (formamidine 12.5'g), pyrethroid (cypermethrin 15'g), and organophosphate (dichlorvos 60'g'+'chlorpyrifos 20'g). Regarding the packet test in both species, resistance was found for the pyrethroid and amidine families in A. mixtum and R. microplus, as efficacy did not surpass 40 %, including in immature instars; regarding the adult immersion test in R. microplus, the efficacy was 93.3 % for the amidine family and 26.2 % for the pyrethroid family. The proposed methodology is an alternative technique to optimize resistance detection in immature ticks with a heteroxenous life cycle.