7.1 Vivid
Dancer: Argia vivida
Order: Odonata
- Dragonflies and Damselflies
Family:
Coenagrionidae - Narrow-winged Damselflies
Status
Global: G5
Provincial: S2
COSEWIC: not addressed
Provincial List: Red
Distinguishing Features
The Vivid Dancer belongs to the family of narrow-winged
damselflies. It is a very intense blue colour with clear wings that
are very narrow at their base. Wings are usually held vertically
when at rest. They are 28 - 43 mm long.
Distribution
Columbia Basin: The Vivid Dancer has only been recorded
from a few locations in the Columbia Basin such as Fairmont Hot
Springs, Field, Meager Creek Hotsprings, Nakusp Hotsprings, Albert
Canyon and in Glacier National Park.
British Columbia: All but two of the known locations
in British Columbia are associated with creeks and ponds surrounding
hotsprings. Outside the Columbia Basin, the only known sites are
a cool spring near Madeline Lake west of Penticton and spring-fed
stream near Okanagan Falls.
North America: Ranges from southwestern Alberta
and southeastern British Columbia south to California, Texas and
Mexico.
Habitat:
Found only in very localised pools near hot springs
or spring-fed streams. It is associated with hot springs at Banff
and Fairmont, and with cold springs at Field and Glacier. Specimens
were found in Albert Canyon, but not in Glacier during 1998 field
surveys (Cannings, pers. Com.).
Threats
Invertebrates such as the Vivid Dancer are not threatened
by direct exploitation, so much as by habitat loss or degradation.
Most accessible hot springs in Alberta and B.C. have already undergone
extensive modification and diversion into swimming pools, and unique
flora and fauna have been lost. Heavy grazing of grasslands and
livestock trampling around the edges of cold springs is another
significant threat.
Biology
Vivid Dancers lay eggs in aquatic vegetation or wet wood, often
submerging for periods up to a half-hour or more. Males protect
females from other males by retaining their mating hold of the female's
thorax and standing stiffly at attention. Larvae are usually found
in running water. The aquatic larvae cling to the undersides of
stones and roots in the small streams and muddy pools. The adults
rest on stones or bare earth nearby, and make short foraging flights
after small insect prey. They are alert, seldom resting in one place
and dodge into vegetation when alarmed.
