Given how similar it looks to a dragonfly, some of you may have thought of one when you first saw this. But it's actually the black torrent dart, or Dysphaea ethela, a damselfly from the Euphaeidae family, according to the Encyclopedia of Entomology.
Ethel Grace Fraser, the spouse of Frederic Charles Fraser and a dependable travel partner on their trip to gather different kinds of insects in India, first gave the name of this species (1881-1960). According to Wikipedia, this species is commonly found in Tamil Nadu, Kerala, and Karnataka, among other states in Southern India.
Meanwhile, I captured these images in Sumatra, Indonesia. Most people who have traveled to Indonesia and southern India will undoubtedly concur that the two places' climates are remarkably similar.
Dysphaea ethela is a medium-sized damselfly with a black head and black eyes covered in brown. It has a black thorax with faint lines that are greenish-yellow in color. The wings have some gray to white patterns and are translucent brown. There are seven segments to the black abdomen.
In rocky rivers and streams, Dysphaea ethela habitats are commonly found reproducing. There are frequently seen perched on shrubs, reeds on the river's banks, or on boulders in the river.