Resin bees of genus Megachile, subgenera Callomegachile and Carinula (Hymenoptera, Megachilidae) from Thailand with description of a new species Author Chatthanabun, Nontawat Center of Excellence in Entomology and Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Ascher, John S. Insect Diversity Lab, Department of Biological Sciences, National University of Singapore, 16 Science Drive 4 S 3 Level 4, 117558, Singapore Author Pinkaew, Nantasak Department of Entomology, Faculty of Agriculture at Kamphaengsaen, Kasetsart University, Kamphaengsaen Campus, Nakhon Pathom, 73140, Thailand Author Thanoosing, Chawatat Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW 7 5 BD, UK & Department of Life Sciences, Imperial College London, South Kensington Campus, Exhibition Road, London SW 7 2 AZ, UK Author Traiyasut, Prapun Program in Biology, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani, 34000, Thailand Author Warrit, Natapot Center of Excellence in Entomology and Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand ich108@hotmail.com text ZooKeys 2020 997 95 144 http://dx.doi.org/10.3897/zookeys.997.34935 journal article http://dx.doi.org/10.3897/zookeys.997.34935 1313-2970-997-95 52E31975D30F4F93BBA3AB628D381281 55136D8014F356BAAB0129717E021D48 Subgenus Callomegachile Michener Chalicodoma (Callomegachile) Michener, 1962: 21. Type species: Chalicodoma mystaceana Michener, 1962, by original designation. Chalicodoma (Eumegachilana) Michener, 1965: 191. Type species: Megachile clotho Smith, 1861, by original designation. Chalicodoma (Morphella) Pasteels, 1965: 537. Type species: Megachile biseta Vachal, 1903, by original designation. Chalicodoma (Orientocressoniella) Gupta, 1993: 165. Type species: Megachile relata Smith, 1879, by original designation [but Gupta's description refers to a bee quite different from the nominal type species, see Baker and Engel 2006 ]. Chalicodoma (Alocanthedon) Engel & Gonzalez, 2011: 53. Type species: Chalicodoma odontophorum Engel, 2011, by original designation. Diagnosis. Body elongate. Female mandible three to seven teeth with minutely roughened ridge. Punctures on mesoscutum and lower part of mesepisternum striated. Small appressed hairs on inner mandibular surface of adductor interspace present. In males, carina on T6 bilobed or lacks median emargination; posterior margin of T6 simple and without tooth. Comments. The subgenus Pseudomegachile Friese, 1898 is superficially similar to Callomegachile , in term of size and appearance. Females of Pseudomegachile can be recognized by the presence of long erected hairs on inner mandibular surface of adductor interspace, whereas males can be easily recognized by the presence of multidentate apical margin of T6.