de Oliveira Patrícia Rosa, Pizano Marcos Aparecido, Remédio Rafael Neodini, Bechara Gervásio Henrique, de Abreu Rusleyd Maria Magalhães, Camargo Mathias Maria Izabel
Department of Biology, Institute of Biosciences, São Paulo State University-UNESP, Av. 24 A, n° 1515, 199, 13506-900, Rio Claro, SP, Brazil.
Department of Ecology, Institute of Biosciences, São Paulo State University-UNESP, Av. 24 A, n° 1515, 199, 13506-900, Rio Claro, SP, Brazil.
Exp Parasitol. 2015 Aug;155:82-8. doi: 10.1016/j.exppara.2015.04.021. Epub 2015 May 5.
Ticks are vectors of several pathogens to vertebrates, including the human being. They produce lesions on the hosts during the blood feeding and great economic losses. Several chemical acaricides have been used in an attempt to control tick infestations; however these substances are harmful to both the human being and non-target organisms, and to the environment. Therefore, there is a need to fight these ectoparasites through less harmful methods, less aggressive to the environment, non-target organisms and to the human health. The present study examined the efficacy of dinotefuran on the susceptibility of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of the product. Its lethal concentration of 50% (LC50) at 95% confidence interval was determined. The ticks were immersed in Petri dishes containing different concentrations of dinotefuran or distilled water for 5 minutes and then dried and maintained in an incubator for 7 days. The results showed the daily number of dead R. sanguineus semi-engorged females after being treated with different concentrations of dinotefuran. The mortality data in bioassay 2 were subjected to Probit analysis, where a LC50 of 10,182.253 ppm (8725.987-13,440.084) and 95% confidence interval were estimated. The susceptibility of R. sanguineus semi-engorged females to dinotefuran in higher concentrations of the acaricide was demonstrated, indicating that its effect is probably dose-dependent. In addition, the action of dinotefuran was slow and gradual, interfering in the development and growth of the individuals throughout the observation period (7 days).
蜱是包括人类在内的多种病原体向脊椎动物传播的媒介。它们在吸血过程中会在宿主身上造成损伤，并带来巨大的经济损失。人们使用了几种化学杀螨剂来试图控制蜱虫侵扰；然而，这些物质对人类、非目标生物以及环境都有害。因此，有必要通过危害较小、对环境、非目标生物和人类健康攻击性较小的方法来对抗这些体外寄生虫。本研究检测了呋虫胺对不同浓度该产品处理的血红扇头蜱半饱血雌蜱易感性的影响。测定了其在95%置信区间下的半数致死浓度（LC50）。将蜱虫浸入含有不同浓度呋虫胺或蒸馏水的培养皿中5分钟，然后晾干并置于培养箱中7天。结果显示了用不同浓度呋虫胺处理后血红扇头蜱半饱血雌蜱的每日死亡数量。生物测定2中的死亡率数据进行了概率分析，估计出LC50为10182.253 ppm（8725.987 - 13440.084）以及95%置信区间。结果表明，较高浓度杀螨剂处理下的血红扇头蜱半饱血雌蜱对呋虫胺敏感，这表明其作用可能具有剂量依赖性。此外，呋虫胺的作用缓慢且渐进，在整个观察期（7天）内干扰个体的发育和生长。
