Cattle ticks Rhipicephalus (Boophilus) microplus are mainly controlled in Brazil by means of acaricide products, without any official policies in this regard. Acaricides continue to be sold indiscriminately, and this has contributed towards making the problem of resistance widespread, thus making diagnosis and monitoring of tick resistance essential. Here, bioassays (larval packet test) were performed on tick populations from the states of Rio Grande do Sul and Mato Grosso do Sul regarding their susceptibility to cypermethrin, deltamethrin and flumethrin. All the tick samples tested showed resistance to cypermethrin (10) (resistance factor (RF) ranging from 5.6 to 80.3) and deltamethrin (10) (RF ranging from 2.4 to 83.1). Six out of eight populations were resistant to flumethrin (RF ranging from 3.8 to 8.2). PCR molecular analyses did not show any T2134A mutations in the voltage-gated sodium channel gene, in any of the sampled populations. The results from this study highlight the critical status of resistance of the cattle tick to synthetic pyrethroids in the regions studied. Further studies are needed to identify the mechanisms responsible for the resistant phenotypes observed in the bioassays. This was the first detection of flumethrin resistance in Brazil.Keywords: Cattle tick, acaricide resistance, synthetic pyrethroids, PCR. ResumoO controle do carrapato Rhipicephalus (Boophilus) microplus no Brasil é feito principalmente com produtos acaricidas, sem uma política de controle oficial. A venda destes produtos continua ocorrendo de maneira indiscriminada, o que tem contribuído para generalizar o problema da resistência em todo o país, tornando essencial seu diagnóstico e monitoramento. Bioensaios (teste do pacote de larvas) foram conduzidos com populações de carrapatos do Rio Grande do Sul e Mato Grosso do Sul, com relação à sua suscetibilidade a três princípios ativos piretróides. Todas as amostras analisadas mostraram resistência à cipermetrina (10), com fatores de resistência (FR) de 5,6 a 80,3, e à deltametrina, com FR variando de 2,4 a 83,1. Seis das oito amostras foram resistentes à flumetrina (FR de 3,8 a 8,2). Análises moleculares utilizando PCR demonstraram que em todas as populações amostradas não foram encontrados alelos com a mutação T2134A no gene do canal de sódio controlado por voltagem. Os resultados deste estudo evidenciam a situação crítica da resistência do carrapato bovino ao grupo dos piretróides sintéticos nas regiões estudadas. Novos estudos são necessários para identificar os mecanismos responsáveis pelos fenótipos resistentes observados nos bioensaios. Este é o primeiro relato da resistência a flumetrina no Brasil.

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Ticks of the Amblyomma cajennense complex present high infestation rates. These ticks transmit the bacterium Rickettsia rickettsii, which causes Brazilian Spotted Fever. For this reason, an integrated tick control system was adopted on a farm in the municipality of Itu, state of São Paulo. On this farm, which borders the Tietê river, domestic animals are in contact with populations of capybaras. Six locations were monitored and evaluated between the years of 2015 and 2017. During this work 1271 nymphs and adult ticks were caught, all of them from the Amblyomma sculptum species, except for a single individual from the Amblyomma dubitatum species. The integrated tick management reduced the overall infestation levels to zero. Adult tick population dropped in the first year of the study, while larvae population dropped in the second year. Nymph population dropped in both years, decreasing in higher numbers in the first year. The estimated mean infestation levels for all of the tick’s life cycle forms in the six monitored spots did not reach one individual in the end of the study. Estimated mean infestation levels for nymphs in these places equaled zero.

Macrocheles is the largest genus in the family Macrochelidae which contains some species that act as biological control agents of pests on crops.

Species in the cohort Uropodina include a great diversity of free-living mites, which inhabit soil, leaf litter and manure. These habitats present favorable microclimatic aspects for colonization and succession of several species of mites, with different niches occupied over time. For poultry manure, many weeks of manure accumulation are necessary for there to be sufficient colonization by predatory and decomposing arthropods, including mite species, and for the formation of complex food webs for ecological stability. The knowledge of manure mite fauna in Brazil is hampered by the great diversity of species and the lack of specialists. In the State of São Paulo, there are few known species of edaphic and manure mites from the cohort Uropodina. This study presents taxonomic and some comparative distribution data about uropodids in poultry manure in the State of São Paulo. The manure was collected in poultry farms in Mogi-Guaçu, SP (1,800 kg) in July 2022. The mites were extracted by Berlese-Tullgren method over an eight-day period and preserved in 70% alcohol. The mites were counted and Uropodina identified by visual observation for clarification and preparation of slides in Hoyer’s medium. The mite specimens were compared with the mites previously collected in manure from a laying farm in Santa Cruz da Conceição, SP in July 2001 and July 2002. Two morphospecies of Thrichouropoda were identified in the samples from Mogi-Guaçu. The mites obtained in Santa Cruz da Conceição, SP had representatives in the genera Uroseius, Uroobovella and Thrichouropoda, with four morphospecies identified. The variation in distribution and diversity of uropodids in the manure of both poultry farms suggest that instabilities regarding the accumulation of manure, management in these properties, environmental changes over the years and factors intrinsic to the locations, could affect the uniformity of collections in these areas. The uropodids from this study were deposited in the Collection of Arthropods of Medical and Veterinary Importance (IB-CPAMV), Laboratory of Animal Parasitology, Biological Institute of São Paulo.