Abstract:
The tick Rhipicephalus microplus (Canestrini) is a major economic hurdle to the global livestock industry. The incorrect and indiscriminate control carried out by synthetic chemical compounds has contributed to the emergence of parasite resistance present today to many products available in the veterinary market. Effective, economically viable and potentially safe alternatives need to be investigated, including herbal medicine and biological control by entomopathogenic fungi. In this study, extracts from Achyrocline satureioides (Lam.) DC. obtained by extraction with solvents of different polarities associated and not associated with the entomopathogenic fungus Beauveria bassiana (Balsamo-Crivelli) Vuillemin were evaluated on different stages of the life cycle of R. microplus. The activity of plant extracts, fungus and their associations in ticks was analyzed in vitro through the adult immersion test, larval packet test and larval immersion test. The highest efficacy on engorged females (43.3%) was reached by the hexanic partition (ASh) at 5 mg/mL + fungus, reducing larval hatchability. ASh associated with B. bassiana also caused high mortality of larvae, reaching LC50 of 6.23 and 2.65 mg/mL in the packet and immersion tests, respectively. The results obtained showed that extracts, when used in combination with the fungus, have their action enhanced, reaching 100% mortality of larvae. Among the evaluated methodologies, it was observed that the larval immersion test allows better assessment, due to the time of contact with the larvae. The results obtained with A. satureioides associated with the fungus are considered promising and open new perspectives for future product development.
摘要:
蜱虫Rhipicephalusmicroplus(Canestrini)是全球畜牧业的主要经济障碍。由合成化学化合物进行的不正确和不加区别的控制导致了今天在兽医市场上可获得的许多产品中存在的寄生虫抗性的出现。有效,需要研究经济上可行和潜在安全的替代方案,包括草药和昆虫病原真菌的生物防治。在这项研究中,Achyroclinesatureioides提取物(Lam。)DC。通过用与昆虫病原真菌白僵菌(Balsamo-Crivelli)Vuillemin相关的不同极性的溶剂提取而获得。植物提取物的活性,真菌及其在蜱中的关联通过成人浸泡试验进行了体外分析,幼虫包试验和幼虫浸泡试验。5mg/mL真菌的六烷分区(ASh)对充血的雌性(43.3%)达到了最高疗效,降低幼虫的孵化率。ASh与B.bassiana也导致高死亡率的幼虫,在包装和浸泡试验中达到6.23和2.65mg/mL的LC50,分别。获得的结果表明,提取物,当与真菌结合使用时,他们的行动得到加强,达到100%的幼虫死亡率。在评估的方法中,据观察,幼虫浸泡试验可以更好地评估,由于与幼虫接触的时间。与真菌相关的A.satureioides获得的结果被认为是有希望的,并为未来的产品开发开辟了新的前景。