Influence of Orientia tsutsugamushi Infection on the Developmental Biology of Leptotrombidium imphalum and Leptotrombidium chiangraiensis (Acari: Trombiculidae)

ABSTRACT Leptotrombidium chiangraiensis Tanskul & Linthicum, and Leptotrombidium imphalum Vercammen—Grandjean are important vectors of scrub typhus in rice field habitats in northern Thailand. The developmental biology of all stages of the life cycle of two generations of these species of mites infected with Orientia tsutsugamushi (Hayashi) and uninfected mites is reported. The development of the infected lines of both F1 and F2 L. chiangraiensis were significantly longer than their respective uninfected lines (P 150 fewer eggs than uninfected mites.