Description of the larva of Indocnemis orang (Förster in Laidlaw, 1907) (Odonata Platycnemididae: Calicnemiinae) from Thailand, with larval key to the known genera of the family Platycnemididae in Asia Author Keetapithchayakul, Tosaphol Saetung Department of Zoology, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd, Lat Yao Chatuchak Bangkok; Author Makbun, Noppadon 211 / 5 Moo 4, Takhli, Nakhon Sawan, 60140, Thailand; Author Phan, Quoc Toan The Center for Entomology & Parasitology Research, College of Medicine and Pharmacy, Duy Tan University, 120 Hoang Minh Thao, Lien Chieu, Da Nang, Vietnam. Author Danaisawadi, Patchara Department of Zoology, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd, Lat Yao Chatuchak Bangkok; Author Wongkamhaeng, Koraon Department of Zoology, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan Rd, Lat Yao Chatuchak Bangkok; text Zootaxa 2022 2022-05-12 5134 4 504 520 journal article 55563 10.11646/zootaxa.5134.4.2 0f7c10de-d119-4071-9f4f-61145babee9c 1175-5326 6541699 B46601AD-4F72-4F78-93DF-5034F0A557A9 Taxonomic key to the known larvae of genera of family Platycnemididae in Asia The larval comparison was based mainly on Orr & Dow (2015b) supplemented with Fraser (1943) ; Lieftinck (1953) ; Eda (1965) ; Ishida (1996) ; Xu (2013) ; Orr & Dow (2016) ; Chen & Yu (2020) ; Saetung et al. (2020) ; Xu (2021) . 1 Labium with one pair of premental setae................................................................... 2 1’ Labium with more than one pair of premental setae.......................................................... 6 2 Palpal setae with same length; vertical lamella caudal gills.................................................... 3 2’ Palpal setae with different length; triquetro - quadrate caudal gills ( Fig. 13A ), triradiate in transverse section.... Calicnemia 3 2–4 palpal setae; weakly and moderately produced ligula; caudal gills with or without petiole......................... 4 3’ 6 palpal setae; strongly produced ligula; foliate caudal gills with distinct petiole ( Fig. 13G ).................. Onychargia 4 3–4 palpal setae; moderately produced ligula; denodate or subnodate vertical lamella caudal gills..................... 5 4’ 2 palpal setae; weakly produced ligula ( Fig. 12D ); nodate vertical lamella caudal gills, oblong shaped ( Fig. 13C )..... Nososticta 5 3 palpal setae; subnodate vertical lamella caudal gills, broad ovate shaped, with nodus on middle and distal thirds ( Fig. 13F )............................................................................................. Caconeura 5’ 3–4 palpal setae; denodate vertical lamella caudal gills, ovate shaped, without nodus ( Fig. 13K )............. Prodasineura 6 Labium with 2 pairs of premental setae.................................................................... 7 6’ Labium with more than 2 pairs of premental setae........................................................... 9 7 3–4 palpal setae; denodate vertical lamella caudal gills........................................................ 8 7’ 4 palpal setae; subnodate vertical lamella caudal gills ( Fig. 13I ) with fimbriated shape.......................... Copera 8 3 palpal setae; moderately produced ligula ( Fig. 12G ); presence of protuberance on occipital margin; body shorter than 1.3 x length of caudal gills........................................................................ Pseudocopera 8’ 3–4 palpal setae; strongly produced ligula ( Fig. 12I ); absence of protuberance on occipital margin; body longer than 1.5 x length of caudal gills......................................................................... Platycnemis 9 3–6 pairs of premental setae; 4–9 palpal setae; subdonate vertical lamella caudal gills.............................. 10 9’ 4 pairs of premental setae; 6–7 palpal setae; triquetro - quadrate type caudal gills ( Fig. 13B ), triradiate in transverse section.......................................................................................... Disparoneura 10 3–4 pairs of premental setae, 4–6 palpal setae; foliate to ovate caudal gills, with or without petiole ( Figs. 13D, 13J ) Coeliccia 10’ 5–6 pairs of premental setae, 8–9 palpal setae; ovate caudal gills, without petiole ( Fig. 13H )................ Indocnemis