Evaluation of the Efficacy of Acaricides Used to Control the Cattle Tick,Rhipicephalus microplus, in Dairy Herds Raised in the Brazilian Southwestern Amazon

Abstract

The adult immersion test (AIT) was used to evaluate the efficacy of acaricide molecules used for control of Rhipicephalus microplus on 106 populations collected in five municipalities in the state of Rondônia in the Brazilian South Occidental Amazon region. The analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. The synthetic pyrethroids (SPs) acaricides were the least effective (48.35–76.84%), followed by SP + organophosphate (OP) associations (68.91–81.47%) and amidine (51.35–100%). For the macrocyclic lactones (MLs), the milbemycin (94.84–100%) was the most effective, followed by spinosad (93.21–100%) and the avermectins (81.34–100%). The phenylpyrazole (PZ) group had similar efficacy (99.90%) to the MLs. Therefore, SP acaricides, including associations with OP, and formulations based on amidine presented low in vitro efficacy to control the R. microplus populations surveyed.

Resistencia in vitro a acaricidas tópicos de poblaciones de garrapatas Rhipicephalus (Boophilus) microplus provenientes de cuatro departamentos de Colombia

“…Al comparar los valores aquí observados entre un 10-20% de eficacia para ambos piretroides con estudios epidemiológicos en regiones brasileñas donde emplearon el mismo protocolo de AIT, los resultados son similares en señalar que en algunas regiones los piretroides han perdido casi toda su eficacia (Raynal et al, 2013). No obstante, en estudios anteriores y de otras zonas brasileñas citan valores de eficacia por encima del 50%, si bien siguen siendo el grupo de acaricidas donde aparece mayor resistencia (Andreotti et al, 2011;Brito et al, 2011). Estudios recientes en 4 fincas de Antioquia han mostrado que para la cipermetrina los valores de eficacia también eran menores del 20%, e incluso del 0% en dos de ellas (Puertas et al, 2015;López et al, 2015).…”

“…En el estudio epidemiológico de Andreotti et al (2011) la variación de eficacia a la combinación clorpirifos + cipermetrina osciló entre un 0 y 100%, resaltando la importancia de hacer el estudio individualizado por predio. Ésta y otras combinaciones de piretroides y organofosforados son ampliamente usadas en Brasil donde se ha observado que, cuando existe resistencia, la asociación de ambas familias aumenta la eficacia de los principios activos de cada una por separado (Andreotti et al, 2011;Raynal et al, 2013, Brito et al, 2011.…”

Comparative in Vitro Study on the Efficacy of Some Commercial Insecticides against Rhipicephalus (Boophilus) annulatus Ticks

“…The continued usage of the same compound for controlling certain insect for long period resulted in developing resistance against the used compound. Many publications documented the resistance of hard tick species to Diazinon; Li et al, (2003), Miller et al, (2008), Fernández-Salas et al, (2012 and Alonso-Díaz et al, (2013) and deltamethrin; Brito et al, (2011), Sharma et al, (2012 and Shyma et al, (2015).So, the current trend in the world now is the use of natural products to overcome the drawbacks of currently used chemicals. In the last decades, plant extracts were widely used against phytophagus pests and mosquitoes (Balandrin et al, 1995).…”

Management of Cattle Ticks Rhipicephalus microplus (Acari: Ixodidae) in Response to the Emergence of Resistance to Synthetic Acaricides

“…Ticks can transmit pathogens such as Anaplasma, Babesia and Theileria responsible for certain parasitosis, (Frisch et al, 1999) that may influence directly or undirectly milk and meat production (Gharbi et al, 2011, Onu et al, 2013. According to Jonsson et al (2006Jonsson et al ( , 1998 cited by Brito et al (2011), ticks negatively affect animal production through the transmission of pathogens agent whose protozoa, rickettsiae and viruses, causing serious diseases in cattle. In addition to these diseases, each engorged female was able to ingest 1.0 ml of blood during its parasitic phase on the bovine, resulting in a weight loss of approximately 1 g and a reduction in milk production 8.9 ml.…”