The orangeblack Hawaiian damselfly was once Hawaii’s most abundant damselfly species likely because of its ability to use a variety of aquatic habitats for breeding sites. Historically, the orangeblack Hawaiian damselfly probably occurred on all of the main Hawaiian Islands (except Kahoolawe) in suitable aquatic habitat within the anchialine pool, coastal, lowland dry, and lowland mesic ecosystems. Currently, Megalagrion xanthomelas is found only on Oahu, Maui, Molokai, and Hawaii where 34 known naturally occurring population units are found (USFWS unpublished data). Megalagrion xanthomelas is in the family Coenagrionidae (pond damsels). It is one of the smaller Hawaiian damselflies, with adults about 33-37 mm (1.3-1.5 in.) in length, with a wingspan of 35-40 mm (1.4-1.6 in.). Males are black with bright red to salmon pink markings on the thorax, as well as on both the first three and the last three segments of the abdomen. Females have a similar pattern but are tan instead of red, and the abdominal segments are black dorsally and tan on the sides and underside (Polhemus & Asquith 1996). Nymphs reach up to 18-20 mm (0.7-0.8 in.) in length. They have three flattened leaf-like gills at the tip of the abdomen; the gills are longer than the combined length of the last five segments of the abdomen, and each comes to a small point at the tip (Polhemus & Asquith 1996).