9种农药对黄瓜新绥螨若螨和卵的影响

本文采用4种方法测定了已测试对黄瓜新绥螨Neoseiulus cucumeris(Oudemans)雌成螨无毒的9种常用农药对其若螨和卵的影响.结果表明:25%噻虫嗪(阿克泰)水分散粒剂和0.5%苦参碱烟碱(果圣)水剂对若螨和卵的LC50分别为3128.49mg·L-1和1802.67mg·L-1、26.37mg·L-1和27.01mg·L-1;喷雾法和二次中毒测定发现这2种农药常规使用浓度对若螨和卵的校正死亡率均低于10%,表明这2种农药对若螨和卵影响很小.0.3%印楝素乳油对若螨和卵的LC50分别为7.43mg·L-1和8.70mg·L-1,喷雾法和叶片残毒法测定发现其常规使用浓度对若螨和卵的校正死亡率分别为5.17%～36.21%和3.95%～28.95%,表明该农药对若螨和卵低毒.80%代森锌可湿性粉剂、80%代森锰锌(大生M-45)可湿性粉剂、50%代森锰锌可湿性粉剂和50%多菌灵+福美双(普雅图)可湿性粉剂常规使用浓度对若螨和卵的校正死亡率均低于5%,表明这4种杀菌剂对若螨和卵无明显影响.86.2%氧化亚铜(铜大师)可湿性粉剂和77%氢氧化铜(可杀得)可湿性粉剂常规使用浓度对若螨的校正死亡率最高分别达到16.81%和9.32%,对卵的校正死亡率均低于5%,表明这2种杀菌剂对若螨低毒,对卵无明显影响.

Effects of Nine Pesticides against the Nymphs and Eggs of Neoseiulus cucumeris(Oudemans)

In this paper,toxic effects of nine pesticides to nymphs and eggs of Neoseiulus cucumeris（Oudemans） were tested using four methods.The 24-h LC50 values of 25% thiamthoxam WG and 0.5% matrine and nicotine AS to nymphs and eggs of N.cucumeris were 3128.49 mg·L-1 and 1802.67 mg·L-1,26.37 mg·L-1 and 27.01 mg·L-1,respectively.The corrected mortalities by the two pesticides were all less than 10% tested by methods of spraying and secondary poisoning,indicating that the two pesticides had little effect on nymphs and eggs of N.cucumeris.The 24-h LC50 values of 0.3% azadirachtin emulsion to nymphs and eggs were 7.43 mg·L-1 and 8.70 mg·L-1,and the corrected mortality was at the range of 5.17%-36.21% and 3.95%-28.5%,respectively,by methods of spraying and secondary poisoning,indicating that 0.3% azadirachtin emulsion had low toxicity to the nymphs and eggs.Also,80% zineb WP, 80% mancozeb M-45 WP,50% mancozeb WP and 50% carbendazim and thiram WP had no toxicity to nymphs and eggs,as indicated by the low corrected mortalities（less than 5%） of these four pesticides. 86.2% cuprous oxide WP and 77% copper hydroxide WP had no toxicity to eggs,as indicated by the low corrected mortalities（less than 5%） of these two pesticides,but the corrected mortalities to nymphs were 16.81% and 9.32%,respectively,indicating that they had low toxicity to nymphs.