农药对稻田捕食性天敌蜘蛛的安全性研究

SAFETY STUDY OF PESTICIDES ON SPIDERS,PREDATORY NATURAL ENEMIES OF PEST,IN PADDY FIELDS

1987～1990年经60余种农药对稻田拟水狼蛛和食虫瘤胸蛛的成蛛毒性测定和田间试验,发现杀虫剂(除少数品种如噻嗪酮、杀虫双、杀虫单等外)对蜘蛛的毒性比除草剂和杀菌剂大.据药量安全指数和48h 的LC_(50),LC_(90)值来看,杀虫剂中拟除虫菊酯、有机氯为类高毒,有机磷中的毒死蜱、甲基对硫磷、杀螟硫磷、辛硫磷、治螟磷、二嗪磷、甲胺磷等对蜘蛛的安全性亦小.蜘蛛对农药敏感,但种类不同敏感性不同,拟水狼蛛比食虫瘤胸蛛对大多数农药的敏感性要大.农药对稻田蜘蛛的急性毒性可分3级,室内评价标准:48h LC_(50)值小于20ppm 时为高毒类,20～150ppm 时,为中毒类;大于150ppm 时,为低毒类.田间评价标准:48h 药量安全指数<1,为高毒类;1～40为中毒类;>40为低毒类.

During 1987 to 1990,sixty pesticides were used in laboratory and paddy field totest their safety on spiders(Pirata subpiraticus and Oedthorax insecticeps).The safety var-ied with different pesticides and application methods.The insecticides were more toxic to spi-ders as compared with herbicides and fungicides.The results also indicated that the followingpesdticideswere high toxic:Pyrethroid,Organochlorine and Pirimiphos ethyl,Parathion-methyl,Fenitrothion,Phocim,Sulfotep,Diazinon,Methamidophos etc.Spraying was moretoxic than toxin soil method.Spiders are susceptible to majority pesticides,especially Piratasubpiraticus.According to the LC_(50)and DSR(dosage safe ratio),the safety of pesticides tospiders was evaluated.The standards in laboratory can be expressed as follow:high toxicity,LC_(50)<20 ppm,moderate toxicity,20～150 ppm;low toxicity,>150 ppm.In paddy field eval-uation standards are as follows:high toxicity,DSR<1:moderate toxicity,1～40;low toxici-ty,>40.