Nine new species groups, 15 new species, and one new subspecies of New Guinea diving beetles of the genus Exocelina Broun, 1886 (Coleoptera, Dytiscidae, Copelatinae)

Nine new species groups of Exocelina Broun, 1886 from New Guinea are introduced with keys to their representatives. Four groups are monotypic and include three new species: the E. aipomek group, the E. koroba group: E. koroba sp. nov., the E. mekilensis group: E. mekilensis sp. nov., and the E. morobensis group: E. morobensis sp. nov. The remaining five species groups include 18 species with 12 new species and one new subspecies: the E. bacchusi group: E. akameku sp. nov., E. oiwa sp. nov., E. oksibilensis sp. nov., and E. bacchusi herzogensis ssp. nov.; the E. jaseminae group: E. aseki sp. nov., E. kailaki sp. nov., and E. pseudojaseminae sp. nov.; the E. larsoni group: E. warahulenensis sp. nov.; the E. takime group: E. mianminensis sp. nov.; and the E. warasera group: E. haia sp. nov., E. kobau sp. nov., E. pulchella sp. nov., and E. warasera sp. nov. Diagnoses of five already described species of these groups are provided, as well as comparatives notes on all species. Exocelina santimontis (Balke, 1998) syn. nov. is a junior synonym of E. aipomek (Balke, 1998). Data on the distribution of the species are given, showing that most of the species of these groups occur in the Papua New Guinea.