Resumen La ivermectina (IVM) es ampliamente utilizada para el control de parásitos en el ganado en los trópicos. La IVM residual en las heces conserva su actividad insecticida durante semanas y puede dañar diversas especies de escarabajos estercoleros. La atracción a las heces del ganado tratado con IVM se probó usando a las especies Onthophagus landolti (Harold) y Canthon indigaceus chevrolati (Harold) como modelos de estudio. Los experimentos se realizaron bajo condiciones de laboratorio controladas, condiciones de campo semicontroladas y condiciones de campo no controladas. Se utilizaron olfatómetros en los ensayos controlados y semicontrolados. El tratamiento de control consistió en heces exentas de IVM, y los tratamientos experimentales fueron heces de ganado tratado con IVM al 1 % (administración subcutánea, dosis única, 0.2 mg / kg pv) las cuales se recogieron a los 5, 14, 21 y 28 días después del tratamiento al ganado. El ensayo de campo no controlado incluyó trampas de caída libre o pitfall cebadas con heces libres de IVM y con heces de ganado tratado con IVM recogido cinco días después del tratamiento. En condiciones controladas y semicontroladas, las heces del ganado tratado con IVM (a los 5, 14, 21 y 28 días después del tratamiento) atrajeron más individuos O. landolti yC. i. chevrolati que las heces sin IVM (P < 0.05). La misma respuesta ocurrió bajo condiciones no controladas. Esta clara atracción a las heces de ganado que contienen IVM por las especies estudiadas pone de relieve que el uso incorrecto de IVM puede plantear un riesgo para las comunidades de escarabajos estercoleros en los sistemas de producción ganadera.

Abstract Ivermectin (IVM) is widely used for parasite control in livestock in the tropics. Residual IVM in feces conserves its insecticide activity for weeks and can harm dung beetle (DB) species. Attraction to the feces of IVM-treated cattle was tested using the DB species Onthophagus landolti (Harold) and Canthon indigaceus chevrolati (Harold) as models. Experiments were done under controlled laboratory conditions, semi-controlled field conditions and uncontrolled field conditions. Olfactometers were used in the controlled and semi-controlled trials. The control treatment was baited IVM-free feces, and the experimental treatments were the feces of cattle treated with 1 % IVM (subcutaneous administration; single, 0.2 mg/kg bw dosage) and collected at 5, 14, 21 and 28 days post-treatment. The uncontrolled field trial involved pitfall traps baited with IVM-free feces or feces from IVM-treated cattle collected five days post-treatment. Under controlled and semi-controlled conditions, the feces of IVM-treated cattle (at 5, 14, 21 or 28 days post-treatment) attracted more O. landolti and C. i. chevrolati individuals than IVM-free feces (P < 0.05). The same response occurred under uncontrolled conditions. This clear attraction for IVM-containing cattle feces by the studied DB species highlights that incorrect IVM use may pose a risk to DB communities in cattle production systems.

Abstract The avermectins, milbemycins and spinosyns are part of macrocyclic lactones (ML) group, endectocides that are obtained by fermentation of different species of soil microorganisms. MLs are widely used in veterinary medicine and agriculture because of their potent activity against nematodes and arthropods. However, these compounds, when disposed in the faeces of animals, cause adverse effects on the edaphic fauna associated to dung. This review aims to document the adverse effects of avermectins and milbemycins on terrestrial invertebrates associated with dung, with emphasis on dung beetles from livestock environments under grazing systems. Information on the chemical structure and toxicological effects were compiled in laboratory and field studies of the compounds most used in domestic ruminants. This information is synthesized in 6 tables, which include the toxicological risk of avermectins (ivermectin, abamectin, doramectin and eprinomectin) and one milbemycin (moxidectin). The information compiled shows that the use of avermectins represents a high ecotoxic risk, especially for the immature stages of dung beetles. Moxidectin has been shown to generate less ecotoxic impact compared to avermectins, but research on this compound is still poor.

Resumen Las avermectinas, milbemicinas y espinosinas forman parte de las lactonas macrocíclicas (LM), endectocidas que se obtienen por fermentación de diferentes especies de microorganismos del suelo. Las LM son usadas ampliamente en medicina veterinaria y agricultura debido a su potente actividad contra nemátodos y artrópodos. Sin embargo, estos compuestos al ser eliminados en las heces de animales, causan efectos adversos sobre la fauna edáfica asociada al estiércol. Esta revisión tiene por objetivo documentar los efectos adversos de las avermectinas y milbemicinas sobre los invertebrados terrestres asociados al estiércol, con énfasis en los escarabajos estercoleros de ambientes ganaderos bajo sistemas de pastoreo. Se compiló información sobre la estructura química y los efectos toxicológicos en estudios de laboratorio y de campo, de los compuestos de mayor uso en rumiantes domésticos. Esta información se sintetiza en 6 tablas que incluyen el riesgo toxicológico de las avermectinas (ivermectina, abamectina, doramectina y eprinomectina) y de una milbemicina (moxidectina). La información compilada demuestra que el uso de las avermectinas representa un riesgo ecotóxico alto, en especial para los estadios inmaduros de escarabajos estercoleros. La moxidectina ha demostrado generar menos impacto ecotóxico en comparación con las avermectinas, pero la investigación sobre este compuesto es aún escasa.

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.