Megalagrion xanthomelas (orangeblack Hawaiian damselfly) is a species of damselfly in the order Odonata and the family Coenagrionidae. The species was first found by G. F. Matthew and described in 1876 by Selys-Longchamps. Classified as an endemic species, the Orangeblack Hawaiian Damselfly can only be found in the forests of the Hawaiian Islands. Derived from a freshwater ancestor, the genus Megalarion consists of very diversified groups of damselflies that can grow between the lengths of 33 to 37 millimeters. Megalagrion xanthomelas are commonly found in calm water sources throughout Hawaii including streams and ponds and is threatened by habitat loss. . Anchialine ponds are a common habitat for Megalagrion xanthomelas to live in which requires the species to adapt to mechanisms of osmor