Chalybeothemis fluviatilis Lieftinck, 1933 Selected references: Chalybeothemis fluviatilis Lieftinck, 1933;— Lieftinck 1954: 143 (first record from Sumatra: Belitung). Diplacodes trivalis (Rambur, 1842);— Pujiastuti et al. 2017: 3, Fig. 3g (?part, first record from mainland Sumatra: South Sumatra). Specimens collected. M1a: 1 ♂ (RER20 _ LIB45; UMRI), 15 i 2020; 1 ♂ (RER20 _ LIB46; RER), 19 i 2020; 1 ♂ (RER23 _ LIB47; UMRI), 12 ii 2023; M1c: 1 ♂ (RER20 _ LIB43; RER), 15 i 2020; 1 ♂ (RER20 _ LIB44; BRIN), 15 i 2020; M1g: 1 ♂ (RER23 _ LIB54; UMRI), 26 i 2020; 1 ♂ (RER20 _ LIB55; RER), 26 i 2020; 1 ♂ (RER23 _ LIB310; UMRI), 2 x 2023; M1j: 1 ♂ (RER23 _ LIB309; BRIN), 2 x 2023; M1l: 1 ♂ (RER23 _ LIB48; BRIN), 15 ii 2023; M1p: 1 ♂ (RER23 _ LIB42; RER), 12 ii 2023; 2 ♂♂ (RER23 _ LIB43, 45; BRIN), 12 ii 2023; 1 ♂ (RER23 _ LIB44; UMRI), 12 ii 2023; M5a: 3 ♂♂ (RER20 _ LIB47, 49, 51; BRIN), 20 i 2020; 2 ♂♂ (RER20 _ LIB48, 50; UMRI), 20 i 2020; 1 ♂ (RER20 _ LIB52; UMRI), 25 i 2020; 1 ♀ (RER20 _ LIB53; BRIN), 25 i 2020; 1 ♂ (RER23 _ LIB38; RER), 9 ii 2023; 2 ♂♂ (RER23 _ LIB39, 41; BRIN), 9 ii 2023; 1 ♂ (RER23 _ LIB40; UMRI), 9 ii 2023; 1 ♂ (RER23 _ LIB160; RER), 6 vi 2023; M12a: 3 ♂♂ (RER23 _ LIB306–308; RER), 29 ix 2023; P5d: 1 ♂ (RER23 _ LIB303; RER), 22 ix 2023; 1 ♂ (RER23 _ LIB304; BRIN), 22 ix 2023; 1 ♂ (RER23 _ LIB305; UMRI), 22 ix 2023. Remarks. Recorded from Riau Province for the first time. There is no previously published record from mainland Sumatra of C. fluviatilis but Pujiastuti et al. (2017) list Diplacodes trivialis (Rambur, 1842) with a photograph (their Fig. 3g) that clearly shows C. fluviatilis rather than the Diplacodes, so at least part of their records are actually of C. fluviatilis. Common on open parts of the streams and rivers in the main part of the Kampar Peninsula, as it often is in low pH waters. Quite abundant on the large pond at location P5d in September 2023 but not even seen there in June 2023.

Published as part of Dow, Rory A., Gesriantuti, Novia, Iqbal, Muhammad, Lupiyan-Ingdyah, Pungki, Periera, John F., Zulya, Shinta O. & Sanders, Bradford M., 2025, Odonata of the Kampar Peninsula: the first systematic survey of Odonata in Peat Swamp Forest in Sumatra, pp. 1-70 in Zootaxa 5732 (1) on page 44, DOI: 10.11646/zootaxa.5732.1.1, http://zenodo.org/record/18019483