Aeshna subarctica
Aeshna subarctica Walker, 1908
Local names: Bog hawker, Hochmoor-Mosaikjungfer, Noordse glazenmaker, Æschne subarctique, Gungflymosaikslända
Species Information
Description
Very similar to A. juncea and occurs in similar habitats. They are difficult to distinguish flying. A. subarctica is in any event darker on the thorax and abdomen, has markings more uniform in colour, often a bit duller and paler. Generally bluish, instead of completely separated yellow and blue as A. juncea. Wings are clear with costa and main veins being more brown than yellow. The spot behind the eyes that A. juncea has is always absent on A. subarctica. On S3 on the abdomen, the male has rather big, wide spots, unlike A. juncea who has narrow wedge-shaped spots here. Upper and lower appendages are wider and rounder than on A. juncea. Ventrally on thorax it has two large yellow spots, where A. juncea has smaller or missing spots. There are two forms of A. subarctica in Europe. The northern can be found from north of Scania, Sweden, and northwards. It has three lesser spots between the bands on the sides of the thorax. The southern form occurs on the European mainland, in Denmark and southern Scania. It has larger spots or a narrow band where the northern form has three lesser spots. Variations between the forms occur.
Size
Habitat
It occurs at acidic moors and sphagnum peat bogs, mires, overgrowing or vegetation rich peat graves and edges of lakes. It strongly favours habitats with floating peat-moss, so called Sphagnum-soup. It is absent in open agricultural landscapes.
Distribution
A circumpolar species with different subspecies in North America (A. s. subarctica) and Europe and Asia (A. s. elisabethae). In Europe it is found mainly in the north, where it reproduces in lowlands. It's common in Fennoscandia, the Baltic states, Poland, Northern Germany, Denmark and the Netherlands. Most likely it is common in all northern parts of European Russia. Only a handfull records are available from Belarus. In southern Europe the species is restricted to higher altitudes, occurring for example in the Hautes Fagnes (Hohes Venn, Belgium), the Vosges and Jura mountains (France), the Black Forest (Germany), the Central Alps, the Bohemian forest and the western Carpathians. It has been recently discovered in the Italian Alps and the Romanian Carpathians. The Romanian locality is at considerable distance from other known habitats, suggesting the species has a wider distribution in south-east Europe than is currently known.
Flight Period
June to September
Behavior
Fund near wet floating sphagnums in which the females lay their eggs and where the larvae lives. It can, and often does, coexist beside similar species on the same locales.
Conservation Status
Similar Species
Aeshna juncea, Aeshna serrata, Aeshna crenata, Aeshna cyanea, Aeshna mixta, Aeshna caerulea
External Links
Genus: Aeshna
Aeshna, or the hawkers or mosaic darners, is a genus of dragonflies from the family Aeshnidae. Species within this genus are generally known as hawkers in Europe or darners in America.
Identification
Aeshna spp. are best identified by excluding other aeshnid genera. The species generally have dark bodies with coloured bands on the thorax and their abdomen is basically dark with a mosaic of paired coloured spots. Males have auricles and an anal triangle of 2-4 cells (except I. isoceles).
Separation from other genera
Brachytron are the closest relative, from which the Aeshnas differ by numerous, although somewhat relative, features. These includes Brachytron having an early flight season, smaller size, hairier body, thinner pterostigma and abdomen not waisted. In the hand it is easier to study diagnostic details of venation and markings. Anax differs in shape and wing venation, but is ruled out in the field by the plain thorax and pale abdomen. They also have a black band on the upperside (except the conspicuous A. immaculifrons). Boyeria and Caliaeschna differ in wing venation.
Separation of the species
A large and diverse group. The majority of the world's species occurs in North America. Each species, except for a few pairs of similar species, has several unique features.
Behaviour
Often seen hawking (hence the common name) in open but sheltered places. I can be glades or gardens, as well as over open waters. Foraging individuals often concentrate at good sites, especially towards the end of the day. Males patrol swiftly over water, often aggressively territorial. They usually follow a fairly fixed and often extensive route, frequently interrupting direct flight with hovering pauses and dashes toward other individuals. A, affinis is the only species that oviposit in tandem with the male, all other Aeshna females oviposit alone.
Family: Aeshnidae
The Aeshnidae, also called aeshnids, hawkers, or darners, is a family of dragonflies. The family includes the largest dragonflies found in Europe and North America and among the largest dragonflies on the planet.
Description
Common worldwide or nearly worldwide. Genera are Aeshna and Anax. The African Anax tristis has a wingspan over 125 mm, making it one of the world's largest known dragonflies. Most European species belong to Aeshna. Their American name darner stems from the female abdomens looking like a sewing needle, as they cut into plant stem when they lay their eggs.
The dragonflies mate in flight. The eggs are deposited in water or close by. The larvae (nymphs or naiads) are generally slender compared to those of other families, with a long and flat extensible lower lip (labium). The larvae are aquatic predators, feeding on other insects and even small fish.
The adults spend large amounts of time in the air and seem to fly tirelessly. They can fly forwards or backwards or hover like a helicopter. The wings are always extended horizontally.
The abdomen are mostly colored blue and or green, with black and occasionally yellow. The large, hemispherical, compound eyes touch in the midline. Individuals of this family have an extremely good sight, and are voracious insect predators.
A proposal has been made to split this family into Aeshnidae and Telephlebiidae.
The name may have resulted from a printer's error in spelling the Greek Aechma, a spear. The spelling Aeschnidae has been intermittently used over a period of time, but is now abandoned for the original name Aeshnidae. However, derived genus names (such as Rhionaeschna) retain the 'sch' spelling, as this is how they were first cited.