INVESTIGATION ON OCCURRENCE AND DISTRIBUTION OF STORED GRAIN CRYPTOLESTES SPECIES IN EIGHTY PREFECTURE-LEVEL CITIES OF TWELVE PROVINCES OF CHINA

Cryptolestesferrugineus(Stephens) wascommon speciesofstored grain insectswhich was cosmopolitan and difficulty to be controlled grain storage.There were about four or five species of Cryptolestes involved in grain storage.There was an obvious significance to know the distribution and occurrence of these species to scientific control.The investigation of on-site insect collection in eighty prefecture-level cities of twelve provinces was carried out in which 570 enterprises were surveyed,includeding grain depots,flour mills,rice mills,farmer storages and grain markets.The investigated provinces included in Hainan,Guangdong,Yunnan,Fujian,Zhejiang,Hunan,Hubei,Henan,Shandong,Shanxi,Liaoning and Heilongjiang province.C.ferrugineus and C.pusillus were found in all surveyed provinces.C.turcicus was founded in ten provinces of twelve surveyed one (excepted for Zhejiang and Shanxi).The new distribution record of C.pusilloides was found in Hainan and Fujian Province which was only recorded in Yunnan Province as before around China.C.pusilloides was collected only in one grain market in this investigation of Yunnan Province.This species was gotten from six enterprises among of seventeen ones surveyed in Hainan Province,including one grain depot,two rice mills and three grain markets.The species also was seen in three enterprises among of forty ones surveyed in Fujian Province,including one grain depot,one rice mills and one flour mills.The collecting frequency of C.ferrugineus,rate on number of collected insect enterprise to surveyed enterprise one,was top level among of four species of the genus.And the frequency was followed by that of C.pusillus,C.turcicus and C.pusilloides from high to low.The collecting frequency of Cryptolestes species in rice mill was on top level among of all surveyed enterprises.