The Studies Of Effective Phosphine Fumigation To The Cryptolestes Ferrugineus And Liposcelididae

In this study,the complete lethal time of different stages of Cryptolestes ferrugineusand Liposcelis bostrychophila with different resistance level have been detected under the laboratory simulation and the practical conditions.FAO recommended method used in this study, to determined the resistance levels of 11 different strains of Cryptolestes ferrugineus(Stephens) the results show that the resistance of the six different strains HNCF1-HNCF6 were 1.4955, 7.7114, 4.0604, 6.8104, 7.8365 and 11.5433 mg/L; The LC50 value of MCCF,XMCF,PTCF,ZZCF,PDSCF strain are 4.1728 mg/L,3.4845 mg/L,4.6769 mg/L,8.7413 mg/L and 9.1869 mg/L; all of them has gained a very high resistance. The resistance levels of eight strains of booklice belong to three different spices has also be determined, there are two strais belong to the Liposcelis bostrychophila(Pearman):the LC50value of the XSGLB strains is 0.0039 mg/L which is sensitive strain;the BJLB strain'sLC50 value is0.0174 mg/L,also three stains categorize as the L.entomophila(Enderlein),the ZXLE strain has the LC50 value of 0.0815mg/L, the ZZLE strain's the LC50 valueis 4.3319 mg/L, the PDSLE strain's LC50 value is 4.4288 mg/L,another three strains of the booklice have been identified as the L.paeta (Pearman): the strains TPLP has a LC50 valueof 0.8843 mg/L, NYLP strain's LC50 value is 0.3135 mg/L; and the theLC50 value of strain CXLP is 0.0804mg/L. the results indicated that:the L.entomophila(Enderlein) own a higher tolerance both than the L.bostrychophila (Pearman)and the L.paeta (Pearman).complete lethal time was determined at five levels of concentration that included 100,200,300,400 and 500 mL/m3 of phosphine separately indoor involved with different states of the Cryptolestes ferrugineus(Stephens), The results show that:under the same phosphine concentration, the mortality rate of each state increased with the time increasing; and when the fumigation time is the same the mortality of various state is directly proportional to the increase of phosphine concentration,but Ct value is the key to prevente and control the pest. to enhance the phosphine concentration aloneor just to improve the exposure time is no guarantee of the pest population extinction.From the CT value ,the tolerance of eggs and pupae are similar but higher than the tolerance of adult which slightly higher than the larvae. For the practical warehouse fumigation, the highest resistance state should be taken as reference to guide the fumi-gation time .In practical storage conditions, different storage types fumigate in different ways, The results show that :the warehouse of mobile recirculation fumigation adding CO2 fumigation has gained the best effect, the effect of arch warehouse-type with the method of natural deliquenscence is the worse, however, for the arch warehouse take the natural deliquenscence method is better.the fumigation results have a positive corre-ction with the air tightness conditions .