Orthetrum erythronigrum sp. nov. (Odonata: Libellulidae) from the Great Nicobar Island, India

The male and female of Orthetrum erythronigrum sp. nov. are described from Great Nicobar Island and are believed to be endemic to the Nicobar Islands archipelago (holotype ♂, India, Andaman and Nicobar Islands, Great Nicobar Island, Great Nicobar Biosphere Reserve, N 6.99067, E 93.871363; 01-xii-2018; deposited in ZSI, SRC, Chennai, India). The male of this new species is easily distinguished from other known Orthetrum species by its black abdomen with contrasting crimson belly. Female is distinguished by its large size, the black non-metallic head, black thorax and the red abdomen with a distinct black pattern. Based on field observations and photographs, notes on the life colouration of the mature male and information on the distribution and habitat of this Great Nicobar endemic are provided.