Aeshna juncea
Aeshna juncea (Linnaeus, 1758)
Local names: Common hawker, Moorland Hawker, Torf-Mosaikjungfer, Venglazenmaker, Æschne des joncs, Starrmosaikslända
Species Information
Description
A. juncea is one of the larger aeshnids and a powerful flyer. As a typical aeshna the abdomen is dark with spots along sides and top of the abdomen
forming a coloured mosaic. On S3 two blue wedges can be found, bases opposing towards each other.
These can be used to distinguish from A. subarctica whose spots have broader shapes. Wings are clear with long pterostigmas and yellow leading margin. On older individuals though, especially females, the wings can take on a light brown tone. Thorax is brown with narrow antehumeral stripes. Thorax sides have two broad bands, coloured blue, green or yellow. Between the band are 1-3 smaller spots. The shape of these spots can be used in separating from similar species, but they can be hard to see due to wear and age. Frons is yellow with a black T-shaped marking. This marking distinguishes it from simillar specie A. serrata whose stem is less distinct. Eyes have a yellow spot on the backside, which distinguishes it from A. subarctica. Variations occur with very small or indistinguishable spots. The male especially, is rather dark, compared to A. cyanea, but often more vivid in colours compared to A. subarctica. Females have two colour forms, one dark body with blue and greyish markings (a lot like the males) or with green spots on the sides of the abdomen and yellow spots on top.
Size
Habitat
It is mostly confined to nutrient-poor, standing and unshaded waters, having a preference for bogs and other standing waters with well-developed Sphagnum vegetation. At lower altitudes in central and western Europe the largest populations are found in larger bogs with peat moss and sedges or rushes. With lesser dense populations it can be found in quarries, dune ponds, fens or peaty areas with fields of water soldier. In Fennoscandia and mountain areas it uses a wider range of waters, and can be found in slow-flowing water, lakes or ponds with sparse vegetation.
Distribution
A. juncea is widespread in Europe and all over the northern hemisphere, present also in Asia as well as North America. In Europe it is common in the north, becoming scarcer and confined to higher altitudes in the south. It is fairly common in the Alps and the Pyrenees, but it is scarce and known only from scattered high altitude locales in south-east Europe and the Iberian Peninsula.
Flight Period
June to October
Behavior
A large and powerful flyer, and both sexes can be active even in bad weather. Males patrol low over to water, searching along edges for females.
Abdomens tend to hang slightly in flight, while A. juncea has a straighter posture. Both sexes hunt high up in treetops and is often seen far from waters,
and sometimes late in evenings. Insect-rich places like open sunlit, clearings, forest roads and forest edges are good places to look for this specie.
Conservation Status
Similar Species
Aeshna serrata, Aeshna subarctica, 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.