Subarctic Azure Maiden
| Subarctic Azure Maiden | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Coenagrion interrogatum | ||||||||||||
| ( Hagen in Selys , 1876) |
The sub-arctic dragonfly ( Coenagrion interrogatum ) is a dragonfly species from the family of slender dragonflies (Coenagrionidae), whose southern distribution limit is further north than that of any other dragonfly species and which is one of the dragonflies with the northernmost and coldest habitat. The larvae, protected by anti-freeze substances in the blood, can be frozen in the ice for wintering. Are populated boreal bogs and swamps, especially the peat moss - quaking at the edges of marsh ponds. The occurrence of the Subarctic Azure Damselfly is usually scattered and rare, the population density is low. Coenagrion interrogatum , along with Coenagrion angulatum and Coenagrion resolutum, is one of three species of azure virgin found in America .
features
Characteristics of the adults
Coenagrion interrogatum has a body length of 28 to 32 millimeters and has hind wings with a length of 17 to 21 millimeters. The basic color of the male adults is light blue, the blue eyes are dark on top, so that they appear to be covered by a cap. The subarctic azure virgin is particularly characterized by the ante-humeral stripes of the lateral thorax . These are slightly wider than the humeral strips and open near the rear end so that they look like an exclamation point. In individual cases the stripes can only be narrowed, even more rarely undivided. The blue sides of the thorax underneath are structured, as is typical for azur maiden, with two fine black lines starting from the base of the wing, of which the lower one is conspicuously widened at both ends. On the underside of the thorax there is an unmistakable Y-shaped drawing that is missing from other slender vials. The second segment of the abdomen has a U-shaped drawing with a flat base and wide legs, which can also be perforated at the kink points. The drawing is sometimes described as reminiscent of a cute, grimacing face with comic-like large eyes. The third segment has a black distal ring, the following segments are blackened to ever larger parts, the fourth segment to half, the fifth to three quarters and the sixth to seven eighths. The seventh segment only has a narrow, proximally located blue ring, at the same time the distal side is also blue, so that, together with the eighth and ninth segments, there is a two and a half segments long blue area, which is unusual for slender vials. The tenth segment is black.
The females are more powerfully built; the chest drawing corresponds to that of the male. The eyes are brown on top over a pale green. The abdomen is predominantly black dorsally with narrow pale rings at the segment buttocks that are wider at segments eight and nine. The first two segments are light, the second has a torpedo-shaped drawing with an extra-wide base. The tenth segment is light. The females also have black markings on the underside of the thorax, as well as distinctive dark streaks lateroventrally of the third to seventh abdominal segment. The female adults appear in two color morphs, usually they are blue like the males (androchrome form), but there are also greenish heterochromic (like the females colored) individuals.
Similar species
Characteristic of C. interrogatum are the perforated ante-humeral strips - although these can also occur in Coenagrion resolutum and Enallagma geminatum - as well as the widening of the lower line of the thorax lateral surfaces and the Y-shaped drawing of the thorax underside. The two and a half segments long blue area of the posterior abdominal segments distinguishes the male adults from the other two azure virgins occurring in North America, which may also show broken ante-humeral stripes. At best, it can still be confused with Enallagma aspersum , which has a similar abdominal markings, but is much slimmer and never has any perforated ante-humeral strips. No other female slender dragonfly in the range has a ninth and tenth, as well as at the distal end of the eighth blue-colored abdominal segment and none has broken ante-humeral stripes.
distribution
The main occurrence of C. interrogatum is predominantly in western Canada and ranges from eastern Alaska to Maine and Newfoundland . The southern limit of distribution is further north than that of any other dragonfly.
The habitat of C. interrogatum are boreal bogs and swamps, especially the peat moss - swinging lawns on the edges of the bog ponds, which are often surrounded by bushes.
The occurrence of the sub-arctic damselfly is usually scattered and rare, the population density is low, so it is usually less common than this in its habitat, which is often inhabited by C. resolutum .
Way of life
The adults prefer to stay in the dense vegetation and can hardly be observed above the open water. Copulating mating wheels can often be found resting in bushes up to head height. The eggs are partly laid with the male attached in flowing sedge or grass leaves and upright stems. More detailed information on reproduction and development of C. interrogatum is not known. Since they live in the same habitat and with the same phenology as C. angulatum and C. resolutum , it is assumed that they have a similar way of life. In Yukon it was observed that the time of hatching of the Sub-Arctic Azure damsel was before that of C. resolutum .
The flight time of the adults depends on the latitude and begins in Eastern Canada in May and extends into August, in Montana into July; in the west in Ontario and Maine the Subarctic Azure Damselfly flies only in June and July, however in Québec from May to September. In southern Wisconsin the flight time is between June and August, in Washington only in July.
Systematics
Coenagrion interrogatum is placed within the slender dragonflies in the genus of the azure maiden ( Coenagrion ), which was created in 1890 by William Forsell Kirby . The genus, which counts 40 species, is mainly found in Europe and Asia and is only represented in America by Coenagrion angulatum and Coenagrion resolutum in addition to Coenagrion interrogatum . C. interrogatum is more closely related to C. resolutum than to C. angulatum , which is also reflected in the choice of their habitats. They prefer raised bogs, whereas C. angulatum is rarely found here. The two species are also physically similar, but C. angulatum is much more powerfully built. All three species have relatives in the Old World , with whom they are more closely related than they are to each other.
Coenagrion interrogatum was first described by Hermann August Hagen in 1876 as Agrion concinnum interrogatum , the specific epithet interrogatum means "questioned", but it is not known what question Hagen had in mind when he named the species. It is sometimes assumed that the name refers to the shape of the ante-humeral stripe, which is more like an exclamation mark than a question mark. The English name "Subarctic Bluet" aptly describes the far north-reaching distribution of the species into the subpolar zone .
swell
literature
- John Acorn: Damselflies of Alberta, Flying Neon Toothpicks in the Grass. University of Texas Press, Austin 2011, ISBN 0-88864-419-1 .
- Robert DuBois: Dragonflies & Damselflies of the Rocky Mountains. Kollath + Stensaas Publishing, Duluth 2010, ISBN 978-0-9792006-8-7 .
- Dennis Paulson: Dragonflies and Damselflies of the East, Princeton Field Guides. Princeton University Press, New Jersey 2011, ISBN 978-0-691-12283-0 .
- Dennis Paulson: Dragonflies and Damselflies of the West, Princeton Field Guides. Princeton University Press, New Jersey 2000, ISBN 978-0-691-12281-6 .
Individual evidence
- ↑ a b c Robert DuBois: Subarctic Bluet. In Dragonflies & Damselflies of the Rocky Mountains , pp. 96-97.
- ↑ a b c d John Acorn: Subarctic Bluet. In Damselflies of Alberta , pp. 81-83.
- ↑ a b c d e f g h Dennis Paulson: Subarctic Bluet. In Dragonflies and Damselflies of the East , p. 83.
- ↑ a b B. C. Jones: Coenagrion angulatum on the website of the EH Strickland Entomological Museum of the University of Alberta . Retrieved April 15, 2013.
- ^ A b Dennis Paulson: Subarctic Bluet. In Dragonflies and Damselflies of the West , pp. 74-75.
Web links
- Photos of "Coenagrion interrogatum" - Subarctic Bluet on odonata.bogfoot.net, with pictures