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United States Department of Agriculture

Agricultural Research Service

Research Project: BIOLOGY AND CONTROL OF TICKS OF VETERINARY AND HUMAN IMPORTANCE

Location: Tick and Biting Fly Research

Title: Rhipicephalus (Boophilus) microplus resistant to acaricides and ivermectin in cattle farms of Mexico

Authors
item Rodriguez-Vivas, Roger -
item Perez-Cogollo, L -
item Rosado-Aguilar, J -
item Ojeda-Chi, M -
item Trinidad-Martinez, I -
item Miller, Robert
item Li, Andrew
item Perez De Leon, Adalberto
item Guerrero, Felix
item Klafke, G -

Submitted to: Brazilian Journal of Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 17, 2014
Publication Date: June 30, 2014
Citation: Rodriguez-Vivas, R.I., Perez-Cogollo, L.C., Rosado-Aguilar, J.A., Ojeda-Chi, M.M., Trinidad-Martinez, I., Miller, R., Li, A.Y., Perez De Leon, A.A., Guerrero, F., Klafke, G.M. 2014. Rhipicephalus (Boophilus) microplus resistant to acaricides and ivermectin in cattle farms of Mexico. Brazilian Journal of Veterinary Parasitology. 23(n.2):113-122.

Interpretive Summary: It has been estimated that if cattle fever ticks reenter the United States from Mexico the cost to the U.S. Cattle Industry would be in the billions of dollars per year. Cattle fever ticks were common to the southern United States until the USDA eradicated them. Along the border between Texas and Mexico an eradication zone is established to continually monitor for tick outbreaks. When ticks are found they are eradicated through the use of acaricides. The development of acaricide resistance in cattle fever tick populations in Mexico is a challenge to the future success of the eradication program. This paper reports on the current state of acaricide resistance in Mexico. This work contributes to the understanding that pesticide resistance is a threat to the United States Cattle Fever Tick Eradicaion Program and the U.S. Cattle Industry. With this information, scientific-based, rational decisions can be made about the future needs of the cattle fever tick eradication program in the United States, thus making the program more cost effective and sustainable.

Technical Abstract: Ticks and the diseases they transmit cause great economic losses to livestock in tropical countries. Non-chemical control alternatives include the use of resistant cattle breeds, biological control, and vaccines. However, the most widely used method is the application of different chemical classes of acaricides, including macrocyclic lactones. Populations of the cattle tick, Rhipicephalus microplus, resistant to organophosphates (OP), synthetic pyrethroids (SP), amitraz, and fipronil have been reported in Mexico. Products containing macrocyclic lactones are the most commonly sold antiparasitic drugs in the Mexican veterinary market. Ivermectin-resistant populations of R. microplus have been reported in Brazil, Uruguay, and especially in Mexico (Veracruz and Yucatan). Although ivermectin resistance levels in R. microplus from Mexico were generally low in most cases, some field populations of R. microplus exhibited high levels of ivermectin resistance. The CHPAT population, originally collected from Yucatan, Mexico, showed a resistance ratio of 10.23 and 79.6 at lethal concentration of 50% and 99%, respectively. Many field populations of R. microplus are resistant to multiple classes of antiparasitic drugs, including organophosphates (chlorpyrifos, coumaphos and diazinon), pyrethroids (flumethrin, deltamethrin and cypermethrin), amitraz and ivermectin. This paper reports the current status of the resistance of R. microplus to acaricides, especially ivermectin, in Mexican cattle.

Last Modified: 11/26/2014
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