Study on trombiculid fauna and seasonal occurrence of several trombiculid species in an endemic area of tsutsugamushi disease

ABSTRACT

The study was carried out in an endemic area of tsutsugamushi disease, Taketa city, Japan, from January to December, 2000. Results: 1018 unengorged larvaes of 14 species were isolated from soil and ground surface by direct method and Suzuki method. Among them Helenicula miyagawai was isolated by only the Suzuki method. Leptotrombidium scutellare and l.pallidum suspected as vectors of tsutsugamushi disease in many areas of Japan were detected in this study. The seasonal occurrence of unengorged larvae of L.scutellare was from October to January with the probable peak in November. While L.pallidum occur almost throughout the year with two peak periods, one in May and the other in September.