SPECIES FACT SHEET

							                          SPECIES FACT SHEET

Scientific Name: Aeshna subarctica
Common Name: Subarctic Darner

Technical Description:
  A large (65+ mm) dragonfly. Adults: These characters identify the family
  Aeshnidae. Eyes are broadly contiguous. When perched, wings are held wide
  open. Body is 65-70 mm long. Abdominal segments have multiple spots or
  none, thorax with two stripes on each side or none. Species is identified by
  two irregular-shaped stripes on sides of thorax that yellow-green below and
  blue above. Male superior appendages are simple and pointed at the tip.
  Abdomen segment ten has large blue spots. Larvae: Identification is difficult
  for non-expert.

Life History:
   In BC, adults fly during mid to late season, from mid-June to early October.
   The life of a single adult is eight to ten weeks. Species spend the winter as
   larvae. Depending on conditions, individuals may spend more than one
   winter as larvae. Washington specimens (all adults) were collected on 28-29
   August. Larvae feed on aquatic animals, including invertebrates and possibly
   small vertebrates. They are visual predators and stalk prey on aquatic
   vegetation. Adults feed on flying invertebrates, probably mostly insects.
   NatureServe designates sightings more than 3 kilometers apart as separate
   populations, but little is known about dispersal and colonization ability. This
   species is a strong flier and may be a good colonist, able to reach sites tens of
   kilometers apart. Upon emergence from the larval stage, young adults
   (tenerals) will disperse from 200 meters to more than a kilometer from the
   water before returning to mate. Some adults will usually be present at
   locations where the species reproduces. Eggs are laid in aquatic moss.

Range, Distribution, and Abundance:
  Range-wide: Widespread across northern Eurasia and North America. Can be
  common in appropriate habitat. Rare and threatened in several places at the
  south edge of the range.

  WA: Two known sites - north end of Davis Lake, Ferry Co., on Colville
  National Forest and Fish Lake, Chelan Co, on Wenatchee National Forest. It
  has been found only once at Fish Lake. Known sites are about 150 miles
  apart. Few surveys have been done between these sites. The main part of the
  range is in Canada. Appropriate habitat occupies a small part of the range.
  No information on population size. Population size is less significant for an
  invertebrate than number of occurrences.

  OR: Two sites are known, at Little Crater Lake Meadow and Clackamas Lake,
  near Timothy Lake on Mount Hood National Forest (Valley 2005). These are
  probably part of one population. The known population is in Clackamas Co.
  Federal Land: Known from three National Forests - Colville and Wenatchee in
  WA and Mt. Hood in OR. It is more likely to be found on other Forests in WA,
  and may also be found farther south in OR. It may occur on Mount Rainier
  and North Cascades National Parks.

Habitat Associations:
  Found in peatlands dominated by aquatic moss - sphagnum bogs and fens.
  Larvae require submerged vegetation. According to Paulson (2005), it was the
  only species flying over the sphagnum mat at Davis Lake.

Threats:
  Range-wide: Species faces few immediate threats. Global warming could
  become a problem.
  WA/OR: The greatest long-term threat is drying of habitat by drought. This
  happened in the early 2000s at Fish Lake, and the species has not been seen
  since, although a thorough survey has not been done. Species is threatened
  by peat mining, grazing of habitat, manipulation of water level, and
  recreation and recreational development. Since it occurs on peat mats,
  management of aquatic vegetation and fish is less of a threat than with open
  water species.

Conservation Considerations:
  Inventory: Survey for new sites, in appropriate habitat, between known sites
  and south, through the WA Cascades.
  Management: Grazing, recreational development such as boardwalks, and
  other activities should be carefully planned where this species is known or
  might be present to reduce potential impacts to sphagnum mats.

Other Pertinent Information:

  References:
  Global References:
  Bright, E. and M.F. O'Brien. 1999. Odonata larvae of Michigan. Online at
  http://insects.ummz.lsa.umich.edu/michodo/test/home.htm

  Canning, R. 1996. The blue darners, dragonflies of the genus Aeshna.
  http://www.royalbcmuseum.bc.ca/nh_papers/aeshna.html . Originally published in
  Cordillera vol. 3(1).

  Hutchings, G.E. 2003. A list of the Odonata of Athabasca Sand Dunes Provincial
  Wilderness Park, Saskatchewan. Argia, 14(4): 5-8.

  Johnson, J., E. Coombs, and S. Valley. 2002. Recent highlights in Oregon. Argia,
  14(2): 11-13.

  Nikula, B.J., J.L. Sones, and J.R. Trimble. 2001. New and notable records of
  Odonata from Massachusetts. Northeastern Naturalist, 8(3): 337-342.

  Paulson, D. 2005. E-mail exchange with John Fleckenstein regarding Odonates.
  Paulson, D.R. and S.W. Dunkle. 1999. A Checklist of North American Odonata.
  Slater Museum of Natural History University of Puget Sound Occasional Paper
  Number 56: 86 pp.

  Valley, S. 2005. E-mail to John Fleckenstein regarding odonates of 25 Dec.

  State References:
  Canning, R. 1996. The blue darners, dragonflies of the genus Aeshna.
  http://www.royalbcmuseum.bc.ca/nh_papers/aeshna.html . Originally published in
  Cordillera vol. 3(1).

  Canning, R.A. 2002. Introducing the dragonflies of British Columia and the Yukon.
  Royal B.C. Museum. Victoria, B.C. 96pp.

  Canning, R.A. 2005. E-mail exchange with John Fleckenstein regarding Odonates.

  Paulson, D. 2005. E-mail exchange with John Fleckenstein regarding Odonates.

  Paulson, D. 2005. Northwest odonates; keys, photos, range, and distribution
  information. Online at
  http://www2.ups.edu/biology/museum/UPSdragonflies.html . Accessed 19 Sept.
  2005.

  Paulson, Dennis. 1999. Dragonflies of Washington. Seattle Audobon Society. Seattle,
  WA. 31pp.

Version:
  Prepared by: John Fleckenstein
  Natural Heritage Program
  Washington Department of Natural Resources
  Date: January 2006

  Edited by: Rob Huff
  Conservation Planning Coordinator
  FS/BLM-Portland
  June 2007