二化螟抗药性检测方法比较和抗药性监测

Comparison of methods for testing insecticide resistance in Chilo suppressalis and the resistance monitored

通过比较分析,筛选出较好的初孵幼虫人工饲料药膜法,并用该法对7个地区的二化螟进行了抗药性监测,研究结果在验证初孵幼虫人工饲料药膜法的同时,为田间用药提供了科学依据。采用4龄幼虫点滴法和初孵幼虫人工饲料药膜法进行测定。结果表明：4龄幼虫点滴法测定仅发现不同药剂对南昌种群的毒力略低于敏感品系（RR 1.3~2.1倍）;但用人工饲料药膜法检测发现,南昌种群对三唑磷（54.2倍）和丙溴磷（63.9倍）已经产生了高水平抗性,对杀虫单（13.4倍）表现为中等抗性,对氯虫苯甲酰胺（5.3倍）和毒死蜱（3.6倍）仅为敏感性下降。抗药性监测结果表明,二化螟对杀虫单、丙溴磷和三唑磷的抗性较为普遍。对于杀虫单的抗性,除重庆万州和江苏扬州种群为低水平抗性（9.0、7.7倍）外,其他地区仍维持在中等抗性水平（13.5~21.7倍）。对于丙溴磷的抗性,除万州种群敏感外,其余6个地区均为中高水平抗性（33.3~86.5倍）。对于三唑磷的抗性,不同地区差异较大,武汉、扬州和万州种群较敏感（1.0~4.0倍）,而湘潭、南昌、桂林和金华种群均达到了高等抗性水平（48.0~128.8倍）。不同地区二化螟对毒死蜱（0.9~8.8倍）、氯虫苯甲酰胺（1.0~9.4倍）、丁烯氟虫腈（0.1~5.3倍）、醚菊酯（0.6~8.8倍）和阿维菌素（0.9~4.5倍）均处于敏感至低抗水平之间。其中,氯虫苯甲酰胺、丁烯氟虫腈和阿维菌素不仅抗性水平低,且毒力水平较高（LC50分别为0.11、0.61和0.04 mg·L-1）,毒死蜱和醚菊酯虽然抗性不明显,但毒力较差（LC50分别为1.93和4.99 mg·L-1）,故推荐防治用药,仍需进一步验证田间防效。结论：人工饲料药膜法和点滴法测得的抗药性趋势一致,但药膜法更加灵敏,测得的抗性更加明显;二化螟对常用杀虫剂的抗性普遍较高,对新型杀虫剂较为敏感,但不同地区有明显差异,这与各地的用药历史有关;不同地区的用药应依据药剂的毒力、当地的抗药性状况,以及田间药效来选择。

This study first tries to select a better method for monitoring the insecticide resistance in Chilo suppressalis（ Walker） by comparison of the topical application treatment and diet surface overlay bioassay with a laboratory susceptible strain and Nanchang field population. And then,for proving the selected method and providing the base for rational insecticide application,the resistance of C. suppressalis collected from seven geographic populations in 2013 was monitored. Topical application treatment and diet surface overlay bioassay were used in this experiment. The results showed that with topical application treatment,Nanchang population was found without obvious resistance to any insecticides tested with resistance ratio（ RR） ranged 1. 3-2. 1. While this population was found developed various level of resistance when tested with diet surface overlay bioassay,triazophos RR 54. 2,profenofos RR 63. 9,monosultap RR 13. 4,chlorantraniliprole RR 5. 3 and chlorpyrifos RR 3. 6. Resistance monitoring showed that the resistance of C. suppressalis to monosultap,profenofos and triazophos were popularly developed. Monosultap resistance was medium（ RR 13. 5-21. 7） in most populations,but low in the population from Wanzhou（ RR 9. 0） or Yangzhou（ RR 7. 7）. Profenofos resistance was high in all populations tested（ RR 33. 3-86. 5） except for Wanzhou（ RR 0. 9）. Triazophos resistance varied with populations,which was high in Jinhua,Nanchang,Xiangtan and Guilin populations（ RR 48. 0-128. 8）,but none was found in Wanzhou,Wuhan and Yangzhou（ RR 1. 0-4. 0）. The resistance to other insecticides tested was found much lower in all populations. The resistance ratio for chlorpyrifos ranged 0. 9-8. 8,chlorantraniliprole 1. 0-9. 4,butene-fipronil 0. 1-5. 3,ethofenprox 0. 6-8. 8,and avermectins 0. 9-4. 5. Of these insecticides,though their resistance was not obvious,chlorpyrifos and ethofenprox were lower in their toxicity to sus-ceptible strain. Thus,field trials should be necessary before recommend for field use. Conclusions： It was found that diet surface overlay bioassay was much more sensitive than topical application treatment. The resistances of C. suppressalis to commonly used insecticides were usually high and newly introduced low,but varied with geographic populations. It might have a relationship with the insecticide application history local. The insecticide selection in borer control practice should be dependent on toxicity of insecticides,resistance level in local,and control effect showed in field trials.