Descriptions of three new cantharid species related to themus (Themus) Senensis (Pic, 1922) (Coleoptera: Cantharidae)

Themus (T.) senensis (Pic, 1922) is redescribed and three new species related to it are described, T. (T.) senensomimus sp. nov. (China, Thailand), T. (T.) bilobatus sp. nov. (Laos, Vietnam) and T. (T.) dalatensis sp. nov. (Vietnam). Each species is provided with illustrations of aedeagus and abdominal sternite VIII of female. T. (T.) senensis is also presented with female genitalia and the new species with habitus of both sexes. A key and a distribution map of the above four species are presented.