Transovarial Transmission Of Orientia Tsutsugamushi In Leptotrombidium Palpale (Acari: Trombiculidae)

Transovarial transmission of Orientia tsutsugamushi in colonies of Leptotrombidium palpale was studied in the parent and F-1 and F2 generations. Both transovarial transmission and filial infection rates were 100% in the parent and F-1 generations of Leptotrombidium palpale. The filial infection rate in the F-1 generation was 100%, but it declined to 94.3% in the F-2 progeny. The sex ratio of the F-1 generation from infected L. palpale was 1:0.8 (male:female) and the proportion of males was relatively high. This study is the first to report on the transovarial transmission of O. tsutsugamushi in L. palpale. High transovarial transmission rates in L. palpale suggest that this species might be one of the major vectors of tsutsugamushi disease in Korea.