The Dragonflies
(Insecta: Odonata)
of the Columbia Basin, British Columbia:
Field Surveys, Collections Development and Public Education
Table
of Contents
Return to Family Macromiidae
Macromia Rambur
At one time there were two species of the Macromiidae
recognized in British Columbia, both in the genus Macromia.
M. magnifica is an uncommon species in southern Interior
valleys. M. rickeri Walker was described as a scarce species
of lowland lakes in the Fraser Valley (Cultus and Kawkawa lakes)
and the Shuswap region, but today is considered by most experts
to be merely a dark form of M. magnifica (D. Paulson, pers.
comm.).
Macromia magnifica MacLachlan*
Western River Cruiser
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Provincial Status
CDC rank: S3
Blue List
Macromia is restricted to warm, wave-washed lake margins and
sandy rivers in southern Interior valleys. Columbia-Kootenay
Distribution
Known only from Christina Lake and its outlet stream, Christina
Creek (Whitehouse 1941, present study).
Global Distribution
Western North America; southern British Columbia south to California
and Arizona (Bick and Mauffray 2000). Faunal element: Cordilleran
(see Appendix 2).
Biological information
The preferred larval habitat is among stones, tree roots, sand or
silt in stream pools or in bays of large, warm lakes. Males patrol
low over the water, in swift, direct flight -- but they are often
seen hawking in open areas at considerable distances from their
breeding habitat. Females lay eggs by striking their abdomens on
the water surface every 1 to 2 metres. The only adult specimen in
the RBCM was collected at Christina Lake on 8 July 1938 (Whitehouse);
although Whitehouse collected the species as early as 3 July there.
Syd Cannings and Leah Ramsay saw adults at Christina Creek on 19
July and 7 August 1999. In the Okanagan Valley, the known flight
period is 13 June to 8 September (S. Cannings, unpubl. data).
Management and protection considerations
This species' lacustrine habitat, like that of the gomphids, is
often shared with intensive human recreation use. Marina developments,
pollution from power boats, and popular swimming beaches all have
potential impact on larval survival. More precise knowledge of larval
distribution would assist in making decisions bearing on the health
of this and other lacustrine dragonflies (e.g. Gomphus graslinellus).
In the riverine environment, the impact of introduced predatory
fish (especially bass) is also of concern, but no data are available.
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