我国储粮害虫玉米象和米象磷化氢抗药性调查

A SURVEY FOR RESISTANCE OF SITOPHILUS ZEAMAIS MOTSCHULSKY AND S.ORYZAE(LINNAEUS) TO PHOSPHINE IN CHINA

采用FAO推荐的磷化氢抗药性测定方法,对采自我国16个省、市、自治区的玉米象Sitophilus zeamaisMotschulsky、米象S.oryzae(Linnaeus)2种重要储粮害虫(共55个品系)进行了抗性测定.结果表明,46个玉米象品系中LC50最高的为0.009 mg/L,在FAO推荐的敏感范围.同时进行的击倒试验表明,这些品系的成虫被2 mg/L PH3击倒所有个体的时间(KDT100),最长的为13.9 min,在敏感标准范围之内.测定的9个米象品系中,抗性品系共6个,占67%,LC50值最大为6.313 mg/L,抗性系数(Rf)高达1 034倍;该品系的KDT100为918 min,为敏感品系(7.8 min)的118倍.与国内外的调查结果相比,我国的玉米象对PH3尚未产生严重抗药性,而米象对PH3的抗药性有增强趋势.

The 55 strains in 2 species of stored grain insects, Sitophilus zeamais Motschulsky and S. oryzae （Linnaeus） were collected from 16 provinces in China. The phosphine （PH3） resistance of them was detected with a method recommended by FAO. The results indicated that the most LC50 of 46 S. zeamais was 0. 009 mg· L^- 1 and less than the value of susceptible strains of FAO＇s standard. And the most KDT100（Knockdown Time of 100% adults） of them was 13.9 rain in 2mg· L PH3. They were less than the standard value of susceptibility too. In 9 strains of S. oryzae, there were 6 resistant strains, accounted for 67% of all. The most LC50 of them was 6. 313 mg· L^- 1. Comparing with the 0. 0061 mg· L^- 1 of susceptible strains , the resistant factor（Rf） was up to 1034 times. Its KDT100 was 918 rain and 118 times of the susceptible strains （7.8 min）. No PH3 resistant strain of S. zeamais was detected in China, but the PH3 resistance of S. oryzae strains increased greatly. The research and management of the resistance is very important.