稻田常用农药对四地区二化螟盘绒茧蜂雌成蜂的触杀毒性

为明确稻田常用农药对二化螟幼虫期优势寄生性天敌二化螟盘绒茧蜂Cotesia chilonis(Mat-sumura)的毒性,采用药膜法在室内测定了7种杀虫剂原药以及18种常用农药制剂对扬州、安吉、金华和乐清4个地区二化螟盘绒茧蜂雌成蜂的触杀毒性。结果表明,7种杀虫剂原药中氟虫腈、毒死蜱和三唑磷对该蜂毒性较高,杀虫单、吡虫啉和阿维菌素次之,氯虫苯甲酰胺则最低。12种杀虫剂制剂中20%氯虫苯甲酰胺悬浮剂和3种阿维菌素相关制剂对该蜂毒性相对较低,其余均具高毒性;4种杀菌剂中的异稻.三环唑对该蜂高毒,苯甲.丙环唑次之,井岗.蜡芽菌(井冈霉素)和盐酸吗啉胍.三氮唑核苷则毒性最低;2种除草剂中苄嘧.丙草胺毒性高于苄.二氯。此外,同一种药剂对不同地区雌蜂的毒性也有所不同。

Contact toxicities of various pesticides commonly applied in the paddy field to Cotesia chilonis female adults from four different locations

A bioassay was conducted using a drug contacting method to determine the contact toxicities of various pesticides commonly used in the paddy field to female adults of Cotesia chilonis (Matsumura) a larval and dominant endoparasitoid of the rice stem borer Chilo suppressalis (Walker) from four different locations including Yangzhou, Anji, Jinhua and Yueqing. The results indicated that among seven technical productions of insecticides, fipronil, chlorpyrifos and triazophos showed higher toxicity to this parasitic wasp, and monosultap, imidacloprid and avermectin showed the moderate toxicity, while chlorantraniliprole exhibited the lowest toxicity. Among twelve kinds of insecticide preparations, chlorantraniliprole SC and three preparations associated with avermectin had relatively lower toxicity to this parasitic wasp, while others had higher toxic effects. Among four kinds of germicides, tricyclazole-iprobenfos showed the highest toxicity, propiconazol difenoconazole showed moderate toxicity, and both of validamycin and moroxydine hydrochloride-ribavirin showed the lowest toxicity. As regard to two kinds of herbicides, bensulfuron-methyl pretilachlor had the higher toxicity to this parasitic wasp by comparison with quinclorac-bensulfuronmethyl. In addition, the same pesticide had different toxicity to the parasitic wasps depending on their sampled locations at some cases.