Roma Gislaine Cristina, de Oliveira Patrícia Rosa, Pizano Marcos Aparecido, Camargo Mathias Maria Izabel
Departamento de Biologia, Instituto de Biociências, UNESP, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, SP, CEP 13506-900, Cx. Postal 199, Brazil.
Exp Parasitol. 2009 Nov;123(3):269-72. doi: 10.1016/j.exppara.2009.08.001. Epub 2009 Aug 11.
Currently, the most efficient and widely used method of tick control still is the treatment with acaricides, especially permethrin (active ingredient of the Advantage, Max3, Bayer), a pyrethroid with neurotoxic action. Due to the wide use of this acaricide in the control of the tick Rhipicephalus sanguineus, this study carried out laboratorial procedures to determine the LC(50) (lethal concentration fifty) of permethrin in semi-engorged females of R. sanguineus. Based on the result of 14 dilutions of permethrin in distilled water and later Probit analysis, the LC(50) of permethrin for R. sanguineus was 2062 ppm (1549-2675 ppm). This work can be used as a protocol with other chemicals, to determinate the LC(50), basic procedure for studies of control, resistance and behavior of ticks treated with acaricides, especially the brown dog tick R. sanguineus. Also, the knowledge of the LC(50) provides information on the potency of chemicals, the sensitivity of Arthropods to them and even estimates on pest control.
目前，最有效且应用最广泛的蜱虫控制方法仍然是使用杀螨剂进行处理，尤其是氯菊酯（Advantage、Max3、拜耳的活性成分），一种具有神经毒性作用的拟除虫菊酯。由于这种杀螨剂在控制血红扇头蜱方面的广泛应用，本研究开展了实验室程序，以确定氯菊酯对半饱血的血红扇头蜱雌蜱的半数致死浓度（LC₅₀）。基于氯菊酯在蒸馏水中的14种稀释液结果及随后的概率分析，氯菊酯对血红扇头蜱的LC₅₀为2062 ppm（1549 - 2675 ppm）。这项工作可作为与其他化学物质相关的方案，用于确定LC₅₀，这是研究杀螨剂处理蜱虫的控制、抗性和行为的基本程序，尤其是棕狗蜱血红扇头蜱。此外，LC₅₀的知识提供了有关化学物质效力、节肢动物对其敏感性的信息，甚至还有害虫控制方面的估计。
