Formosan damselfly

Males have a black head and thorax with a bright orange red abdomen tipped in black, reddish brown hook shaped marks on the sides of the thorax, and hindwings that are dark brown along most of their length. Females are duller, with a black abdomen marked by a yellow line along each side and mostly transparent wings.

Adults perch on rocks and streamside plants over clear hill streams, and females are unusual among damselflies in submerging fully underwater to lay eggs on rocks or waterlogged wood, a behavior noted as particularly distinctive among Taiwan's damselflies.