Megalagrion xanthomelas

Appearance

Since the genus Megalagrion is native to the Hawaiian Islands, the species has been exposed to adaptive radiation causing varieties within the species especially in color. Due to adaptive radiation within Hawaiian Megalagrion damselflies, species exhibit a variety of colors ranging from blue, green, yellow, orange, and red. Megalagrion xanthomelas have red males and brown females, thus the common name orangeblack Hawaiian damselfly.

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.

Matthew and described in 1876 by Selys-Longchamps.

Range and habitat

Megalagrion xanthomelas is commonly found near the coastal wetlands of the Hawaiian Islands. The species is also found in wetlands fed by basal springs and different levels of elevation throughout the Hawaiian Islands. Megalagrion xanthomelas is usually found between the range of 60 to 610 meters above sea level, with some populations recorded as high as 1000 meters above sea level.

Classified as an endemic species, the orangeblack Hawaiian damselfly can only be found in the forests of the Hawaiian Islands. Around the early 1900s, Megalagrion xanthomelas was one of the most common species found on the Hawaiian Islands.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Breeding

The first stage of the life cycle is the egg stage that lasts about 21 days before the larva emerges. When females lay their eggs, they lay their eggs fully submerged within aquatic plants.

In crisis

Megalagrion xanthomelas are commonly found in calm water sources throughout Hawaii among them streams and ponds and is threatened by habitat loss. Osmoregulation leads to an increase in diversity within the species causing western coast populations to adapt and be less sensitive to higher salinity habitats, creating a salinity tolerance, while eastern coast populations lack a high salinity tolerance. After World War II, Megalagrion xanthomelas showed an extremely fast decline in population numbers, resulting in many Hawaiian Islands no longer being the home for any populations since the 1990s.

Megalagrion xanthomelas is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Megalagrion xanthomelas, Wikidata item Q1308122. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.