我国储粮书虱磷化氢抗性调查及测定

以联合国粮农组织推荐的储粮害虫磷化氢(PH3)抗药性鉴别剂量(0.03mg·L-1,熏蒸24 h),对采自我国12个省23个地市粮库的4种储粮书虱,嗜虫书虱Liposcelis entomophila(Enderlein),无色书虱L.decolor(Pearman),小眼书虱L.paeta Pearman,虚伪书虱L.mendax pearman的成虫进行抗药性测定.结果表明,嗜虫书虱14个品系采自9个省份,成虫死亡率为0～14%(死亡率越小,说明PH3抗性越强,以下情况相同),其中9个品系小于10%,四川洪雅SCHYLe1品系为0;无色书虱13个品系采自9个省,11个品系的死亡率小于5%,其中广东茂名GDMMLd1品系为0,云南曲靖YNQJLd1品系为100%;小眼书虱3个品系死亡率最高的为4%,浙江萧山ZJXSQLp1品系为1%;虚伪书虱3个品系中,江苏盐城JSYCLm1品系死亡率为5%.对4种书虱中死亡率最低的和最高的品系进行PH3毒力测定,SCHYLe1、GDMMLd1、ZJXSLp1和JSYCLm1等4个品系的LC50值分别为:1.4379,1.3085,0.5476和0.0632 mg/L,SCHYLe1和GDMMLd1的抗性系数分别为80和165倍.可见我国储粮书虱对PH3已产生了严重抗药性,应引起储粮工作人员的高度重视.

RESISTANCE TO PHOSPHINE IN PSOCID(PSOCOPTERA) OF STORED GRAIN IN CENTRAL STORAGES IN CHINA

Grain in central storages was sampled for psocid (Psocoptera) resistance investigation to phosphine in 23 regions in 12 provinces of China. Population samples were then tested for resistance to phosphine (PH3) using a modified FAO method with a discriminating dose (DD) of 0.03 mg L -1 PH3 and a 24 h exposure period.Four species of psocid were detected:Liposcelis entomophila (Enderlein) (15 strains),L. decolor (Pearman) (15 strains),L. paeta Pearman (3 strains), and L. mendax Pearman (1 strain). Results revealed that almost all population samples contained large numbers of individuals that survived from the DD.15 strains of L. entomophila tested,14 from 9 provinces showed mortality from 0 to only 14% at the DD with 9 strains having less than 10% mortality. No susceptible strains of this species were found and the most resistant strain (labeled SCHYLe1) gave 0% mortality.Similarly,11 strains of L. decolor, showed less than 5% mortality at the discriminating dose.Strain GDMMLd1 showed the highest resistance with 0 mortality at the DD, while one apparently susceptible strain was detected:YNQJLd1 with 100% mortality.Mortality at the DD was also low in L. paeta (maximum 4%) with the highest resistance,strains of ZJXSLp1 were 1% mortality.The single L. mendax strain tested,JSYCLm1, gave 5% mortality at the DD. No susceptible strains of either L. paeta or L. mendax were detected. Full dose-response assays were undertaken on the strain with the highest frequency of resistance from each species and on the apparently susceptible L. decolor strain YNQJLd1. LC 50 values for SCHYLe1,GDMMLd1, ZJXSLp1 and JSYCLm1, respectively,were 1.4379,1.3085,0.5476 and 0.0632 mg L -1 .Compared with the LD 50 of 0.0079 mg L -1 for YNQJLd1, 0.0179 for Qle-1, the resistance factors of GDMMLd1 and SCHYLe1 were 165 and 80,respectively. Our survey has revealed that serious resistance to phosphine in psocid species is widespread in Chinese grain storages.