Aeshna canadensis

 
Common Name:
Canada Darner
Odonata
Order:
Odonata
Suborder:
Anisoptera
Family:
Aeshnidae
Genus:
Aeshna
Species:
A. canadensis
The Name
Canada Darner, Aeshna canadensis (Walker, 1908), is a species of dragonfly in family Aeshnidae. It is common throughout southern Canada and the northern United States. Aeshna canadensis occurs in ten provinces and one territory in Canada and twenty four states in the United States of America. 

The Canada Darner is a member of the family Aeshnidae. Darners are among the largest and fastest-flying North American dragonflies, 2 1/4-4 3/4" (57-120 mm) long. These brilliant blue, green, or brown insects have large, clear wings spanning up to 5 7/8". Their compound eyes meet on top of the head. The female hovers above water usually attached or guarded by the male and, using a well-developed ovipositor for slicing into emergent plants, thrusts eggs one at a time in the stems. Preferred habitat includes wooded lakes and ponds with abundant vegetation, as well as marshy and boggy lakes, fens, and slow sluggish streams often associated with beaver ponds. Wetland systems: Western Emergent Marsh, Northern Rocky Mountain Wooded Vernal Pool and the Rocky Mountain Subalpine-Montane Fen.

Very similar to Green-striped Darner.  If the anterior lateral stripe is all blue, the ID is fairly straightforward, but in as many as 10% of New Jersey males, it is partially or completely green, similar to Green-striped.  In Canada Darner, the notch in this stripe usually forms a 90 degree or sharper angle. Patrolling Canada Darners do not look as bright as Green-striped.

Canada Darner usually shows a small spot between the lateral thoracic stripes, absent in Green-striped Darner.  Unfortunately, some male Canadas, usually the ones that most closely resemble Green-striped, lack this spot as well.  Intermediate individuals must be ID'd by examination of the cerci under magnification.  Many books tell you that you can feel small bumps on the cerci of Canada, but Green-striped cerci feel rough as well, although the bumps are smaller.
 
 

 

The Characteristics
Length typically 68-74 mm. The eyes are blue, blue-gray, or green. The abdomen is very dark with blue spotting on all the segments. Females are much like the males, but instead of being blue the markings are green to green-yellow. Sometimes females have amber-tinted wings.

The Canada Darner is one of 11 species of Aeshnid darners found in Alberta. Look for this amazing aerialist throughout summer. The Canada Darner can be found in central and southern Alberta.

Like all Aeshnids, the Canada Darner exemplifies the aerial supremacy that dragonflies are known for. They possess the beautiful mosaic pattern of green, blue and yellow markings on the abdomen that characterize Aeshnid darners. Darners can be difficult to tell apart. Some clues to the identity of the Canada Darner are that the face is light green with a light brown line; the last abdominal segment has pale spots, and the thoracic stripes are bold. The forward edge of the first stripe is strongly indented with an approximately right-angled notch in the front edge of the front thorax stripe. There is also a small spot between the two stripes, at about the same height as the notch. As with all darners, the large all-seeing eyes touch each other at the top of the head. The dark wing spots are narrow and elongate. 

Often associated with bogs and beaver ponds; also occurs at lakes and ponds with abundant emergent vegetation in forest zone. May be found in feeding swarms away from water.  Breeds in squishy ponds, small lakes and slow streams. Males patrol above the shoreline vegetation, keeping an eye out for females, also for rival males. Their patrol is usually at a height of about three feet, and they stop often to hover.

Adults fly from June to October.
 
 

 

The Reproduction and Development
Male Canada Darners patrol relatively small territories along the water's edge, often hovering for significant periods before flying into vegetation looking for females. Copulation usually occurs in vegetation near water. Females oviposit (lay eggs) above the waterline in the stalks of emergent vegetation, slicing into the plant with their ovipositor. 

Larvae feed on a wide variety of aquatic insects, such as mosquito larvae, other aquatic fly larvae, mayfly larvae, and freshwater shrimp. They will also eat very small fish and tadpoles. Adult- The dragonfly will eat almost any soft-bodied flying insect including mosquitoes, flies, small moths, mayflies, and flying ants or termites.
 
 

 

The Distribution
Abundant in many areas throughout its range, common all across North America and there is no indication of any population decline nor are any threats currently identified. 
 
 

 

The Protection Status
IUCN Red List as Least Concern. Common and abundant throughout its range.
 

References:
http://en.wikipedia.org/wiki/Aeshna_canadensis
http://www.iucnredlist.org/details/165074/0
http://fieldguide.mt.gov/detail_IIODO14020.aspx
The Species on Stamps
Canada
2007.10.12

 
 
 
 
 

 


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