三种杀虫剂对稻螟赤眼蜂种群增长的影响

作者评价了3种杀虫剂对稻螟赤眼蜂的卵、幼虫、蛹和后蛹(羽化前)的毒性,并应用实验种群生命表技术研究了对其当代种群增殖的影响。结果表明,在日本农药的常规使用剂量(1000×)下,吡虫啉和优乐得对稻螟赤眼蜂的4个虫态的毒性均较低,且对其当代种群的增长均无不良影响;而杀螟松对其毒性较高,且对当代种群的增长有显著的抑制作用。用杀螟松处理后蛹和幼虫,成虫羽化后仅能存活2～3h;处理蛹,其当代成虫能存活1天,但80％的雌蜂不能产卵,其r_m为负值;仅在卵期处理时,当代种群稍有增长,但R_0、r_m显著低于对照。作者认为,赤眼蜂卵期对农药的耐受力相对较强,吡虫啉和优乐得是协调化学防治和生物防治的理想药剂。

THE EFFECTS OF IMIDACLOPRID AND BUPROFEZIN ON POPULATION MULTIPLICATION OF TRICHOGRAMMA JAPONICVM, EGG PARASITE OF RICE BORER

The toxicity of 3 kinds of insecticides on the egg,larvae,pupae and postpupae of Trichogramma japonicum was studied and the effect of the insecticides on the population multiplication of this generation was also studied by life table method. The results showed that under the routine dose of pesticide in Japan, the toxicity of Imidacloprid and Buprofezin was lower than that of Sumithion for all the 4 developmental stage of T. japonicum ,and all the population multiplication of the parasite for this generation had no harmful effects. And the population multiplication of the parasite for this generation treated with Sumithion was significantly affected, when the postpupae and lavae were treated with Sumithion, all emerged adults were killed for 2 to 3 h after emergence. When the pupae was treated with Sumithion the original generation adult could be alive one day,but 80 percent of female adults could not oviposit and the rm became negetive. While the eggs being treated with Sumithion the population multiplicated a little,but the R0 and rm were lower than that of check. It was suggested that endurance on insecticide was relatively high for the wasp at the egg stage,and Imidacloprid or Buprofezin is satisfactory insecticide for coordinated chemical control with biological control.