Notes on the two Species of Siphunculata or Sucking-lice occuring on Rattus spp. in the Malayan and Pacific Regions, with Special reference to Java

In another paper (Thompson, 1938) attention is called to the fact that specimens of lice from any of the numerous species and subspecies of the widely distributed genus Rattus and its allies should prove interesting, and might possibly throw some light on the relationships of their hosts. The notes contained in this paper are primarily based on a collection of lice obtained by Dr. Felix Kopstein from various species of Rattus in Java. I should like to express my gratitude to Dr. Kopstein for the opportunity of examining this interesting collection. It is to be hoped that these notes may stimulate interest in the lice of rats. The Indo-Australian and Pacific regions have a particularly rich rat fauna and specimens of lice from any forms are needed for study. I am fully aware, however, that lice are not abundant on rats, in fact in my own experience the percentage louse infestation is normally very low. Dr. Kopstein collected 96 specimens of Rattus spp. and only approximately 20 % were parasitised by lice. The two species of lice occurring on the Javanese rats are Polyplax spinulosa (Burm.) and Hoplopleura oenomydis Ferris. The former is unquestionably the normal parasite of the domestic rats: Rattus rattus (Linn.) 1) and R. norvegicus (Berkenhout) 2). With regard to H. oenomydis Ferris, which was originally described from specimens collected from the following hosts and localities: Oenomys bacchante Thomas and Grammomys surdaster polionops Osgood, British East Africa, R. calcis Hollister, and Limnomys mearnsi Hollister, Philippine Is., I feel that no statement could be better than that of Ferris (1932) which reads as follows: "It may be concluded, then, that in all probability H. oenomydis is one of those species which are capable of rather ready, even though erratic, transfer from one host species