Ecological Study of Chigger Mites in Frontiers of Korea Russia and Jilin Province of China

The results are reported in this paper of ecological study of chigger mites in frontiers of Korea,Russia and Jilin province of China during 1990-1995. 5 161 chigger mites belonging to 4 genera and 13 species were recorded from Hunchun and Helong city. The predominant species were Neotrombicula tamiyai (36.0%),N.pomeranzevi (15.9%),Leptotrombidium zeta (14.9%) and N.japonica (11.3%).The composition of species of chigger mites varies with different habitats,mice and months.The mouse with the higherst infested rates by the chigger mits was Clethrionomys rutilus(92.0%).Microtus fortis has the highest infested index (91.5) by the chigger mites. The active durations were 135 days for L.zeta, 105 days for N.pomeranzevi, 75 days for N. microti and 60 days for M.esoensis. During active seasons,there was only peak for L.zeta,N.pomeranzevi,N.microti and M.esoensis.