Infestations with cattle tick, Rhipicephalus microplus constitute the most important ectoparasite problem in the tropical and subtropical regions of the globe, resulting in major economic losses in the cattle production. The control of R. microplus is mostly based on the use of ixodicides. Nevertheless, the irrational use of such products has resulted in tick populations exhibiting resistance to all major ixodicide drug classes. This has urged the development of control alternatives, including the use of animal husbandry practices, selection of tick-resistant cattle breeds, plant extracts, grassland management, vaccination (anti-tick vaccine) and biological control. Integrated tick management consists of the proper combination of at least two control tools aiming to destabilize the constitution of populations with higher proportions of genetically-resistant individuals, while maintaining adequate levels of animal production. The purpose of this paper is to present an updated review on the use of different integrated tick control for the control of R. microplus in the cattle livestock.

Las infestaciones de la garrapata del ganado, Rhipicephalus microplus, producen el mayor problema global de ectoparásitos en ganado de regiones tropicales y subtropicales, provocando grandes pérdidas económicas en la producción bovina. El control de R. microplus se basa principalmente en el uso de ixodicidas; sin embargo, su uso irracional ha propiciado la aparición de garrapatas resistentes a las principales familias de ixodicidas. Esto hace necesario el desarrollo de alternativas de control, incluyendo el empleo de prácticas de manejo en los animales, selección de razas de bovinos resistentes a las garrapatas, uso de extractos de plantas, manejo de pastizales, vacunación (vacuna anti-garrapata) y control biológico. El manejo integral de garrapatas consiste en la apropiada combinación de al menos dos herramientas de control para romper el equilibrio de poblaciones con alta proporción de individuos genéticamente resistentes, manteniendo un adecuado nivel de producción en los animales. El objetivo del presente artículo es presentar una revisión actualizada del uso de diferentes manejos de control integrado de garrapatas para el control de R. microplus en la ganadería bovina.

Carrapatos e as doenças por eles transmitidas causam grandes perdas econômicas ao gado dos países tropicais. Alternativas não-químicas incluem o uso de raças de gado que sejam resistentes, controle biológico e vacinas. No entanto, o método mais utilizado é a aplicação de diferentes classes químicas de acaricidas e lactonas macrocíclicas. Populações de piolhos de gado, Rhipicephalus (Boophilus) microplus, resistentes aos organofosfatos (OP), piretoides sintéticos (SP), amitraz e fipronil, foram descritas no México. Lactonas macrocíclicas são as drogas antiparasitárias mais vendidas no mercado veterinário mexicano. Populações de R. (B.) microplus resistentes à irvemectina foram relatadas no Brasil, Uruguai e especialmente no México (Veracruz e Yucatan). Embora os níveis de resistência à ivermectina no R. (B.) microplus do México tenha sido relativamente baixa, na maioria dos casos, algumas populações campestres de R. (B.) microplus mostraram altos níveis de resistência à ivermectina. A população CHPAT mostrou uma razão de resistência de 10,23 e 79,6 na concentração letal de 50% e 99%, respectivamente. Muitas populações campestres de R. (B.) microplussão resistentes a múltiplas classes de drogas antiparasitárias, incluindo organofosfatos (clorpirifós, coumafos e diazinon), piretoides (flumetrina, deltametrina e cipermetrina), amitraz e ivermectina. Este artigo relata o estado atual de resistência do R. (B.) microplus aos acaricidas, especialmente ivermectina, no gado mexicano.

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 and macrocyclic lactones. Populations of the cattle tick, Rhipicephalus (Boophilus) microplus, resistant to organophosphates (OP), synthetic pyrethroids (SP), amitraz and fipronil have been reported in Mexico. Macrocyclic lactones are the most sold antiparasitic drug in the Mexican veterinary market. Ivermectin-resistant populations of R. (B.) microplus have been reported in Brazil, Uruguay and especially in Mexico (Veracruz and Yucatan). Although ivermectin resistance levels in R. (B.) microplus from Mexico were generally low in most cases, some field populations of R. (B.) microplus exhibited high levels of ivermectin resistance. The CHPAT population showed a resistance ratio of 10.23 and 79.6 at lethal concentration of 50% and 99%, respectively. Many field populations of R. (B.) 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. (B.) microplus to acaricides, especially ivermectin, in Mexican cattle.

The persistent efficacy of 3.15% ivermectin (3.15% IVM) and 10% moxidectin (10% MOX) against natural Rhipicephalus (Boophilus) microplus infestations in cattle in the Mexican tropics was evaluated. Thirty three (33) female cattle were distributed among three treatment groups (n=11), a) 3.15% IVM (0.63 mg/kg body weight subcutaneously; b) 10% MOX (1 mg/kg body weight, subcutaneously; c) non-treated controls. Numbers of adult ticks were determined on d 0, 3, 7, 14, 35, 56, 63, 70, 77, 84, 91, and 98 post-treatment (PT). On d 56, 3.15% IVM and 10% MOX showed similar (P>0.05) persistent efficacy rates: 95.0 and 99.9 %, respectively. Nevertheless, on d 70 PT 10% MOX had higher persistent efficacy than 3.15% IVM (96 vs 66.2 %, P<0.01). It was concluded that the extended persistent efficacy of both 3.15% IVM and 10% MOX given subcutaneously for the control of R. (B.) microplus populations shows that these macrocyclic lactones can be an alternative for the control of cattle ticks in the Mexican tropics. Persistent efficacy of moxidectin was higher than that of ivermectin.

Se evaluó la persistencia de la eficacia de ivermectina-3.15% (IVM-3.15%) y moxidectina-10% (MOX-10%) contra infestaciones naturales de Rhipicephalus (Boophilus) microplus en bovinos del trópico mexicano. Para ello se utilizaron 33 bovinos hembras que fueron distribuidos en tres grupos (n=11) recibiendo los siguientes tratamientos: a) IVM-3.15% (0.63 mg/kg de peso vivo por vía subcutánea; b) MOX-10% (1 mg/kg de peso vivo por vía subcutánea); c) grupo testigo. El número de garrapatas adultas fue determinado los días 0, 3, 7, 14, 35, 56, 63, 70, 77, 84, 91 y 98 postratamiento (PT). La IVM-3.15% y MOX-10% presentaron persistencia de eficacias similares (P>0.05) de 95.0 y 99.9 % respectivamente al día 56 PT. Sin embargo, la MOX10% presentó mayor persistencia de la eficacia que la IVM-3.15% (96 vs 66.2 %, P<0.01) al día 70 PT. Se concluye que la prolongada persistencia de la eficacia de IVM-3.15% y MOX-10% vía subcutánea para el control de poblaciones de R. (B.) microplus demuestra la factibilidad de estas lactonas macrocíclicas como alternativa de control de garrapatas en bovinos del trópico mexicano. Se demostró que la moxidectina presenta mayor persistencia de la eficacia que la ivermectina.