Reaching lengths of over 5 cm, the River Jewelwing is one of Canada's largest damselflies, and also one of the most spectacular. The River Jewelwing (Canada rank: Secure) is found in all the provinces and in Nunavut. Commonly found along the shores of rivers and large creeks, this damselfly has a beautiful, butterfly-like flight.
Female River Jewelwings lay their eggs in the stems of submerged aquatic vegetation, 30 cm or more below the surface of the water; females can remain submerged for half an hour or more, while laying their eggs! Once hatched, the larvae spend at least two years in the water, before metamorphosing into adults. Adult River Jewelwings are distinguished by their spectacular metallic green bodies and their broad wings, which appear as if the outer half has been dipped in black ink. Adult females spend much of their time foraging in upland habitat and only return to the water to mate and lay eggs. Males however, spend most of their time defending their territories along the banks of rivers and large creeks. Once a female enters a male's territory, the male initiates an elaborate courtship dance. First, the male conducts a display flight over a potential egg-laying site in his territory. The flight displays the handsome markings on the hindwings and this may assure the female that he is of the correct species and a suitable mate. Next the male hovers in front of the female, until she allows him to mate. Finally, the female lays her eggs and the life cycle begins again.
The combination of being easy to observe and manipulate, together with a wide distribution and complex behaviour patterns, make these damselflies an excellent study species for a range of behavioural and ecological questions. River Jewelwings have taught scientists much about damselfly movement through upland habitat, courtship behaviour, and species discrimination during courtship. For both amateurs and professionals, these beautiful damselflies are endlessly fascinating to observe.