Three new species of Oocyclus Sharp, 1882, with additional records from China (Coleoptera, Hydrophilidae, Laccobiini).

Three new species of the water scavenger beetle genus Oocyclus Sharp, 1882 from China (Oocyclusextensus sp. nov., from Xizang, O.latiorificialis sp. nov. and O.ximaensis sp. nov. from Yunnan) are described and illustrated in detail. Additional faunistic data, illustrations of habitus and male genitalia, and a key to Chinese species are provided.

Two new species of Platynectes Régimbart, 1879 from China with notes on other Chinese members of the genus, including a key to species (Coleoptera: Dytiscidae: Agabinae).

Two new Platynectes species, P. maizuqii sp. nov. from Guangdong and P. pangu sp. nov. from Yunnan, are described. New records are provided for the following species: P. davidorum Hájek, Alarie, Stastný & Vondrácek, 2019 from Jiangxi, P. dissimilis (Sharp, 1873) from Guangxi, P. gemellatus Stastný, 2003 from Hunan and Zhejiang, P. kashmiranus lemberki Stastný, 2003 from Xizang and P. nanlingensis Stastný, 2003 from Jiangxi. Additional records are also given for most other Chinese species. Platynectes kashmiranus kashmiranus J. Balfour-Browne, 1944 is removed from the Chinese fauna. The habitus of all and the male genitalia of most species are illustrated. An updated key to all Chinese species of Platynectes is provided.

A review of Copelatus Erichson, 1832 of Mainland China, with description of ten new species from the japonicus complex (Coleoptera: Dytiscidae: Copelatinae).

The species of the genus Copelatus Erichson, 1832 from China Mainland are reviewed. 22 species are recorded in total. Ten new species: C. dentatipenis sp. nov. (Fujian, Hunan, Jiangxi), C. diversistriatus sp. nov. (Yunnan; Laos, Myanmar, Thailand), C. felicis sp. nov. (Yunnan), C. miaowangi sp. nov. (Guizhou), C. mopanshanensis sp. nov. (Yunnan), C. nanlingensis sp. nov. (Guangdong), C. puzhelongi sp. nov. (Yunnan; Laos, Vietnam), C. rosulae sp. nov. (Yunnan), C. tengchongensis sp. nov. (Yunnan), and C. xiniudong sp. nov. (Guizhou) are described. Copelatus chinensis Rgimbart, 1899 is reinstituted as a valid species with Copelatus collocallosus Falkenstrm, 1932 and C. collocallosus Falkenstrm, 1933 as its junior subjective synonyms. One species from Hongkong remains unidentified since it is so far known only from a limited number of females. Additional records are provided for the known species; three species: C. bacchusi Wewalka, 1981, C. malaisei Guignot, 1954 and C. parallelus Zimmermann, 1920 are recorded from China for the first time. Copelatus takakurai Sat, 1985 is withdrawn from the Chinese fauna. All species are diagnosed, and their habitus and male genitalia are illustrated. An updated identification key to Chinese Copelatus is provided.

Hyphalus shiyuensis sp. nov. from Xisha Islands, China (Coleoptera, Limnichidae, Hyphalinae).

Hyphalus shiyuensis sp. nov. is described from Xisha Islands of China, which represents the ninth species and provides new distribution information for this unique intertidal genus. Brief comparisons between the new species and the known species are given. An updated key to the species of genus Hyphalus is provided.

A preliminary phylogeny of the Pentatomomorpha (Hemiptera: Heteroptera) based on nuclear 18S rDNA and mitochondrial DNA sequences.

Pentatomomorpha is the second suborder in size only to Cimicomorpha in Heteroptera. However, the phylogenetic relationships among members of the suborder are not well established. Sequences from partial nuclear ribosomal 18S gene and mitochondrial COX1 gene were analyzed separately and in combination to generate a preliminary molecular phylogeny of Pentatomomorpha based on 40 species representing 17 putative families. Analyses of the combined sequence data provided a better-resolved and more robust hypothesis of Pentatomomorpha phylogeny than did separate analyses of the individual genes. The phylogenies were mostly congruent with morphological studies. Results strongly supported the monophyly of the infraorder Pentatomomorpha, and the placement of Aradoidea as sister to Trichophora. The monophyletic Trichophora was grouped into two major lineages, one being the superfamily Pentatomoidea, and the other comprising Lygaeoidea, Coreoidea, and Pyrrhocoroidea. The analysis of the ML and ME trees of combined dataset supported the monophyletic Pentatomoidea. In all analysis the Pyrrhocoroidea was polyphyletic; the monophyletic Lygaeoidea was supported only in the analysis of ME tree, and Coreoidea was polyphyletic except in the MP tree of combined dataset. The molecular and morphylogical data both indicated that the family Coreoidae should be revised subsequently. Our phylogenetic results suggested that the COX1 segment alone might not be an optimal molecular marker for the phylogeny of Pentatomomorpha.