抄録
Experimental infection with tsutsugamushi disease were carried out using albino rats in the noxious area in Niigata Prefecture. Cages containing experimental rats were exposed in the area about 20 hours in each time and these experiments were done from April to October in 1958. Positive results were obtained in a group of 9 rats in August. Two species, 15 individuals of Trombicula i. e. one of T. akamushi and 14 of T. pallida, exclusive of 1 damaged unknown species were found on the rats infected with tsutsugamushi disease.
