Checklist of the dragonflies and damselflies (Insecta: Odonata) of Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka

A checklist of the dragonflies and damselflies occurring in Bangladesh, Bhutan, India (including Andaman and Nicobar Islands), Nepal, Pakistan and Sri Lanka is presented. In total 588 (including 559 full species) taxa are known to occur in the region of which 251 taxa (species subspecies) are single country endemics. Recent taxonomic changes relevant to the area are summarized. Sixteen taxa are synonymized and a checklist of all synonyms established since 1950 is provided. Information is given on available larval descriptions including a list of genera present in the region for which no larvae have yet been described. Numerous species occurring in the area are still poorly known and a list of genera for which a revision is urgently needed is provided.                The following new synonyms are established: Calicnemia sudhaae Mitra, 1994 = Calicnemia imitans Lieftinck, 1948 syn. nov.; Ceriagrion fallax cerinomelas Lieftinck, 1927 = Ceriagrion fallax Ris, 1914 syn. nov.; Ceriagrion fallax pendleburyi Laidlaw, 1931 = Ceriagrion fallax Ris, 1914 syn. nov.; Coenagrion kashmirus Chowdhary Das, 1975 = Ischnura forcipata Morton, 1907 syn. nov.; Enallagma insula Fraser, 1920 = Aciagrion occidentale Laidlaw, 1919 syn. nov.; Himalagrion pithoragarhicum Sahni, 1964 = Ceriagrion fallax Ris, 1914 syn. nov.; Ischnura bhimtalensis Sahni, 1965 = Ischnura rubilio Selys, 1876 syn. nov.; Onychargia indica Sahni, 1964 = Paracercion calamorum (Ris, 1916) syn. nov.; Anaciaeschna kashmirense Singh Baijal, 1954 = Anaciaeschna martini (Selys, 1897) syn. nov.; Cyclogomphus vesiculosus Selys, 1854 = Cyclogomphus ypsilon Selys, 1954 syn. nov.; Chlorogomphus brittoi Navás, 1934 = Chlorogomphus xanthoptera (Fraser, 1919) syn. nov.; Hylaeothemis indica Fraser, 1946 = Hylaeothemis apicalis Fraser, 1924 syn. nov.; Sympetrum durum Bartenef, 1916 = Sympetrum striolatum commixtum Selys, 1884 syn. nov.; Sympetrum himalayanum Navás, 1934 = Sympetrum hypomelas (Selys, 1884) syn. nov.; Sympetrum haematoneura Fraser, 1924 = Sympetrum speciosum Oguma, 1915 syn. nov.; Sympetrum speciosum taiwanum Asahina, 1951 = Sympetrum speciosum Oguma, 1915 syn. nov.                In addition, Periaeschna lebasi Navás, 1930 is regarded a nomen nudum. The following new combinations are proposed: Onychogomphus acinaces Laidlaw, 1922 is transferred to the genus Melligomphus Chao, 1990 resulting in Melligomphus acinaces (Laidlaw, 1922) comb. nov. Onychogomphus saundersii Selys, 1854 is transferred to the genus Nychogomphus Carle, 1986 resulting in Nychogomphus saundersii (Selys, 1854) comb. nov..