Infestation of cattle with the Amblyomma mixtum tick in the states with the largest livestock inventory in Mexico

Abstract

Background. The Amblyomma mixtum tick is one of the main parasites affecting cattle in Mexico. Epidemiological records of A. mixtum in leading states in the national cattle industry, such as Jalisco, Chiapas, Michoacan, Tabasco and Veracruz, are outdated, since this tick species was previously classified as A. cajennense. Objective. Update the records of the A. mixtum tick in the states of Jalisco, Chiapas, Michoacán, Tabasco, and Veracruz, as well as the main ixodicide molecules used for its control. Methodology. From March 2022 to July 2023, ticks were collected from cattle in 46 bovine production units (UPB) distributed in the states mentioned above. Identification was performed using standardized taxonomic keys. Scanning electron microscopy was performed on specimens corresponding to A. mixtum. Results. Of a total of 619 specimens of the genus Amblyomma from 22 UPB, it was confirmed that 100% correspond to the species A. mixtum. Amitraz, an ixodicide molecule belonging to the chemical class of amidines, was used in 63.2% of the UPBs where the presence of A. mixtum was also reported. Conclusions. This research confirms the infestation of cattle with A. mixtum in states with the highest cattle production in Mexico. Further studies with a focus on resistance and extension are required to prolong the usefulness of available tools, including ixodicides, for integrated control of A. mixtum infestations where this tick infests cattle in Mexico.