Two new species of Copelatus Erichson, 1832 from urban low mountains of eastern China, with new province records of the other Copelatinae in China (Coleoptera: Dytiscidae)

Based on the oblong-oval body shape, elytral striation consisting of six dorsal and a submarginal stria with sutural stria complete, and the median lobe of aedeagus without a distinct process, both species are assigned to the Copelatus japonicus complex of the C. irinus species group. They are compared with similar Chinese species, including the co-occuring ones. Their important morphological characters are photographed.

Copelatus chinensis Régimbart, 1899, C. japonicus Sharp, 1884, and Austrelatus parallelus (Zimmermann, 1920) are recorded for the first time from Jiangsu and C. weymarni Balfour-Browne, 1947 for the first time from Heilongjiang and Jilin. Data on the ecology and distribution of the species are provided and illustrated.