New species of caddisflies (Trichoptera, Ecnomidae, Polycentropodidae, Psychomyiidae) from Mekong tributaries, Laos Author Laudee, Pongsak Department of Fishery and Costal Resources, Faculty of Science and Industrial Technology, Prince of Songkla University, Surat Thani Campus, Muang District, Surat Thani Province, Thailand https://orcid.org/0000-0003-3819-7980 pongsak.l@psu.ac.th Author Seetapan, Kriengkrai School of Agriculture and Natural Resources, University of Phayao, Tumbol Maeka, Muang District, Phayao Province, Thailand Author Vongsombath, Chanda Faculty of Environmental Sciences, National University of Laos, Dong Dok Campus, Vientiane, Laos Author Malicky, Hans Sonnengasse 13, A- 3293 Lunz am See, Austria text ZooKeys 2020 962 1 11 http://dx.doi.org/10.3897/zookeys.962.52759 journal article http://dx.doi.org/10.3897/zookeys.962.52759 1313-2970-962-1 CA7DEA7CBFEB4BC8A598A802941FD59F AD14C60754A7579492E50291C659E3C6 Ecnomus petchanaae Laudee & Malicky sp. nov. Figure 1 Diagnosis. The male genitalia of E. petchanaae sp. nov. are similar to Ecnomus gapit Cartwright, 1994, E. yuleae Cartwright, 1994, E. dares Malicky, 2000, and E. perseis Malicky, 2008 described from Borneo. The superior appendages of all these species, including the new species, are particularly large and the subapical part of the superior appendages is covered by numerous spiny setae. However, E. petchanaae sp. nov. can be distinguished by the shape of its superior appendages, which, in lateral view, are slender and club-shaped, but basally broad in E. gapit , E. yuleae , E. dares , and E. perseis . In addition, in ventral view of the outer surface of the inferior appendages of the new species is crescent-shaped, whereas they are curved and claw-shaped in E. gapit , E. yuleae , E. dares , and E. perseis . Figure 1. Ecnomus petchanaae , sp. nov. Male genitalia. A Segment IX and superior appendages, dorsal B segments IX and superior appendages, left lateral C segment IX and inferior appendages, ventral D phallus tip, ventral. Ter IX = tergum IX, Ste IX = sternum IX, Sup = superior appendage, Inf = inferior appendage. Description. Adult, male, length of each male forewing 5.6-6.0 mm; color in alcohol of head, thorax, forewings, abdomen, and legs brown. Male genitalia as in Figure 1A-D . Tergum IX somewhat square, anterior margin truncated, posterior margin bilobed in dorsal view (Fig. 1A ); trapezoid and rounded anterodorsally in lateral view (Fig. 1B ). Sternum IX ovoid in lateral view (Fig. 1B ); rectangular with 1/4 concave incision posteriorly, bilobed and rounded anteriorly in ventral view (Fig. 1C ). Superior appendages long, slender, with expanded base, curved inward posteriorly with numerous long spiny setae subapically in dorsal view (Fig. 1A ); in lateral view, superior appendages, relatively large, long, slightly curved upward, bulb-like apically, with numerous spiny setae (Fig. 1B ). Inferior appendages tubular, bent inward, beak-like apically in lateral view (Fig. 1B ); in ventral view, crescent-shaped, with a submediate knot, overlapping each other subapically (Fig. 1C ). Phallus long, tubular, curved upward, pointed apex with dorsal process in lateral view (Fig. 1B ); in ventral view, bulb-like, with pointed apex (Fig. 1D ). Type material. Holotype. Male. Laos: Pakse Province : Paksong, Vang Ngao River, 15°11'37"N , 106°06'40"E , elev. 920 m, 7.iv.2019, Pongsak Laudee. (PSUNHM). Paratypes : same data as the holotype, 3 males: 1 male (PSUNHM), 1 male (CHM), 1 male (NMPC). Etymology. The species epithet honors Mrs Kanchanaluk Petchana, Director of Administration and Strategic Development Division, Prince of Songkla University, Surat Thani Campus.