抄録
The author has collected three species of fleas from the bodies and the nests of Eurasian small flying-squirrels, Pteromys volans amygdali (Thomas, 1906). They are : 1. Hystrichopsylla microti Scaron, 1950, 2. Rhadinopsylla japonica Sakaguti & Jameson 1956, 3. Monopsyllus argus (Rothschild, 1908). A single specimen of Hystrichopsylla microti was found in the nest but not found on the bodies of mammals. This species has hitherto been found on the wild vole of Microtus montebelli, house rat of Rattus rattus and some insectivora such as Talpa micrura and Urotrichus talpoides. Pteromys volans amygdali seems not the only host of this flea. The last two species, Rhadinopsylla japonica and Monopsyllus argus are found both on the bodies and in the nests of the flying-squirrel, sometimes separately and sometimes together. The former is rather scarce and the latter occurs more abundantly. But both species of fleas are also collected from the bodies and the nests of white-cheeked giant flying-squirrel, Petaurista leucogenys, which is a larger species but has the same habitat as Pteromys volans. Rhadinopsylla japonica is strictly confined to these two flying-squirrels, Monopsyllus argus, however, although found frequently on these two flying-squirrels, also occurs occasionally on a Eurasian squirrel, Sciurus vulgaris together with the allied species, Monopsyllus indages. However, Monopsyllus argus rarely occurs on Martes melampus. Both species of the host, flying-squirrels which are parasitised by both species of fleas, Rhadino-psylla japonica and Monopsyllus argus show closely similar living habits. Sometimes the nest of the small Pteromys volans is occupyed by the large Petaurista leucogenys. It is, therefore, supposed that Pteromys volans amygdali discussed in this paper is the true host of the two species of fleas, Rhadinopsylla jopcnica and Monopsyllus argus, as well as Petaurista leucogenys which is a larger species of Pteromys volans amygdali.
