泽蛙(蝌蚪)和蜘蛛对农药的敏感性与急性毒性分级

THE SUSCEPTIBILITY OF MARSH FROG (TADPOLE) AND SPIDERS TO PESTICIDES AND CLASSIFICATION OF ACUTE TOXICITY

泽蛙和蜘蛛是稻田害虫的重要天敌。通过室内和田间毒性试验，发现它们对拟除虫菊酯、有机氯、沙蚕毒素及治螟磷等农药，特别是对拟除虫菊酯的纯活性异构体敏感．蝌蚪群体异质性比蜘蛛小，对农药更敏感．根据田间毒性试验，室内用４８小时的致死中浓度，田间用安全浓度和药量安全指数，可评价农药对它们的安全性，其急性毒性可分为剧毒、高毒、中等毒和低毒四级．

The Marsh frog and the spiders are important natural enemies to insect pests in paddy fields. According to tests in laboratory and paddy field, it was found that they are susceptible to pyrethroid, organochlorine, nereistoxin, sulfotep, etc., especially to the pure active stereo-isomer in pyrethroid. Because the heterogeneity of tadpole population is lower than that of the spiders, the tadpoles are more susceptible to the pesticides. The results of toxicity tests in paddy fields showed that LC50(48h) in laboratory and the DSR (dosage safety ratio) and LC0(safe concentration) in field could be used to evaluate the safety to these natural enemies while spraying pesticides. The toxicity could be graded into four classes: extra high toxicity, high toxicity, moderate toxicity, and low toxicity.