吡虫啉、烟碱对枸杞蚜虫的毒力测定及防治试验

TEST OF TOXICITIES OF IMIDACLOPRID AND NICOTINE TO WOLFBERRY APHIDS (APHIS SP.) AND FIELD CONTROLLING EXPERIMENT

本文采用点滴法测定了吡虫啉、烟碱对宁夏 4个地区枸杞蚜虫种群的毒力。结果表明 :吡虫啉对不同地区种群的毒力存在较大差异 ,LD50 分别在 6 .7317× 10 - 4～ 1.2 971× 10 - 2 μg .头- 1之间 ;烟碱对不同地区种群的毒力则较一致 ,LD50 分别在 1.16 40× 10 - 1～ 4 .6 814× 10 - 1μg .头 - 1之间。以平吉堡种群作为相对敏感品系 ,惠农、芦花台、中宁种群对吡虫啉的抗性分别增加了 6 .5、10 .0和 19.3倍 ,处低至中抗水平 ;对烟碱的RR值在 1.1～ 4 .0之间 ,处敏感性下降阶段。各药剂的毒力顺序由大到小为 :吡虫啉 >氰戊菊酯≈呋喃丹 >氯氰菊酯 >溴氰菊酯 >灭多威 >久效磷 >甲基对硫磷 >氧乐果 >烟碱。田间药剂防治试验结果表明 ,2 .5 %扑虱蚜可湿性粉剂 37.5g(ai) /hm2 、18.75g(ai) /hm2 和 2 9%油酸烟碱·氯氰乳油 6 5 2 .5g(ai) /hm2 剂量防治枸杞蚜虫效果较好 ,1～ 7d药效均在 80

The toxicities of imidacloprid and nicotine to wolfberry aphids (Aphis sp. ) from 4 areas of Ningxia were examined with topical application methods. The results showed that the toxicities of imidacloprid to the aphids had a big differences with LD 50 values in 6.7317×10 -4 -1.2971×10 -2 ug.aphid -1 separately, and nicotine had a consistent toxicities to the aphids. As compared with the relative toxicity baselines obtained from the field strain in Pinjipu, the strains from Huinong, Luhuatai and Zhongning had increased low moderate resistences to imidacloprid (RR being in 6.5, 10.0 and 19.3 folds separately), and susceptibilities of the wolfberry aphids to nicotine had been in the decreasing stages. Field experiment to control wolfberry aphid had been carried out, it was found that the efficiences of 2.5% imidacloprid WP at the rates of 37.5g(ai)/hm 2 or 18.75g (ai)/hm 2 and 29% oleic acid-nicotine-cypermethrin EC at the rates of 652.5g(ai)/hm 2 were all over 80% during seven days.