7种拟除虫菊酯农药对卤虫的急性毒性研究

为了研究7种拟除虫菊酯农药对美国大盐湖卤虫(GSL Artemia)的急性毒性效应,挑选18~24 h内孵出的卤虫,继续培养24 h后得到Ⅱ~Ⅲ龄卤虫无节幼体,将其暴露于所设浓度梯度的拟除虫菊酯溶液中进行24 h急性毒性实验,记录卤虫无节幼体在各浓度溶液中的死亡情况,并将所得数据进行Probit分析。结果表明,卤虫对不同拟除虫菊酯的敏感性相差较大。氯菊酯、氯烯炔菊酯、炔咪菊酯、胺菊酯、联苯菊酯、高效氯氟氰菊酯和溴氰菊酯对卤虫的24 h半致死浓度(24 h-LC50)分别为4.68、14.82、18.12、38.21、>100、>100和>100 mg.L-1。因此,在含有卤虫的盐水环境中,应尽量避免使用毒性较高的氯菊酯,而选择使用联苯菊酯、高效氯氟氰菊酯和溴氰菊酯等毒性较低的农药。

Acute Toxicity of Seven Pyrethroid Insecticides to Brine Shrimp Artemia

To study the acute toxic effects of seven pyrethroid insecticides on the Great Salt Lake (GSL) Artemia, Artemia nauplii hatched out within 18-24 h were picked out, and then continued to be cultured for another 24 h under the same condition to obtain the 2nd-3rd instar nauplii. The obtained GSL Artemia were exposed to different concentrations of pyrethroid solutions for 24 h, and the lethal effects were recorded. The results of Probit analysis showed that lethal effects of the seven studied pyrethroids on GSL Artemia were very different from each other. The 24 h median lethal concentrations (24 h-LC₅₀) of permethrin, chlorenthrin, imiprothrin, tetramethrin, bifenthrin, lambadacyhalothrin, deltamethrin to brine shrimp were 4.68, 14.82, 18.12, 38.21, >100, >100, >100 mg·L^-1, respectively. Therefore, in the Artemia-living saline environment, the pyrethroid insecticides with relatively lower toxicity including bifenthrin, lambadacyhalothrin and deltamethrin should be given prior consideration rather than the highly toxic permethrin.