The Life Cycle of the Scrub Typhus Chigger Mite, Trombicula akamushi1

Results are presented on observations of the life cycle and biology of the chigger mite, Trombicula akamushi (Brumpt) reared under constant environmental conditions in the laboratory. The entire life cycle required 46 to 72 days, and data on the development of the various stages are presented. Observations made on the subsequent development of groups of larvae which had been fed on rodents or on chicks indicated that engorgement on the former led to more rapid development. Of particular interest were observations made on sex determination, which indicated that while some females produced both male and female offspring, most females produced offspring of only one given sex.