Four new species of Agraphydrus Régimbart (Coleoptera: Hydrophilidae), with additional faunistic records for China

Four new species of Agraphydrus Régimbart are described from China: Agraphydrus danxiaensis sp. nov. from Guangdong, A. mutatus sp. nov. from Jiangxi, and A. xieweicaii sp. nov. and A. zhangyouxiangi sp. nov. from Hunan. Three species are recorded for the first time from China: A. biprojectus Minoshima, Komarek & Ôhara, 2015, A. nepalensis Komarek, 2018, and A. nemorosus Komarek, 2019. Additional faunistic data are provided for the following Chinese species: A. anhuianus (Hebauer, 2000), A. audax Komarek & Hebauer, 2018, A. calvus Komarek & Hebauer, 2018, A. cantonensis Komarek & Hebauer, 2018, A. chinensis Komarek & Hebauer, 2018, A. confusus Komarek & Hebauer, 2018, A. contractus Komarek & Hebauer, 2018, A. fasciatus Komarek & Hebauer, 2018, A. fikaceki Komarek & Hebauer, 2018, A. globipenis Komarek & Hebauer, 2018, A. gracilipalpis Komarek & Hebauer, 2018, A. igneus Komarek & Hebauer, 2018, A. robustus Komarek & Hebauer, 2018, A. umbrosus Komarek & Hebauer, 2018, A. variabilis Komarek & Hebauer, 2018, and A. yunnanensis Komarek & Hebauer, 2018. A new colouration form of A. yunnanensis is described. An updated list of Agraphydrus species occurring in China is provided.