Transovarial Transmission of Rickettsia Tsutsugamushi in Leptotrombidium (Leptotrombidium) Arenicola Traub (Acarina: Trombiculidae)1

Leptotrombidium (L.) arenicola, described by Traub in 1960, has previously been shown to harbor Rickettsia tsutsugamushi , the causative agent of scrub typhus. In an attempt to establish the epidemiological importance of L. (L.) arenicola in the transmission of scrub typhus, studies of the behavior of R. tsutsugamushi in this vector were instituted. Transovarial transmission of R. tsutsugamushi through 2 generations of this trombiculid mite was demonstrated. In addition, these experiments showed that L. (L.) arenicola larvae can transmit scrub typhus rickettsiae during feeding on a mammalian host. Because L. (L.) arenicola is widely distributed along the sandy shorelines of both the eastern and western sides of the Malay peninsula. it is concluded that this vector may have considerable epidemiological importance in the transmission of scrub typhus.