Aeshna cyanea
Aeshna cyanea (Müller, 1764)
Local names: Southern hawker, Blue hawker, Blauflügel-Prachtlibelle, Blauwe glazenmaker, Æschne bleue, Blågrön mosaikslända
Species Information
Description
One of the larger of the hawkers, close in size to A. juncea. Mature males abdomen has paired green spots on the upper side of S1-S7, in marked contrast to light blue spots on the sides and on S8-S10. The last two segments, S9-S10, have each a light-blue band on the upper side. On top of S2, A. cyanea has a yellow wedge-shaped spot, like A. mixta, but larger.
The females are brown with aqua-green markings similar to those of the males. In both sexes, the sides of the thorax is mainly green with blackish thick lines, one completely crossing, one only half-way up. The rear margin of the eye is dark with two characteristic yellow spots, visible from the side. Broad shoulder-lines are often easily visible in flight.
Size
Habitat
Aeshna cyanea is found at standing, and less often at slow-flowing waters. It has a clear preference for small and at least partly shaded habitats. On larger water bodies it favours sections that are visually demarked from the main area of water, for example by higher vegetation. Often the bottom is partly free of emergent vegetation. Such situations occur in ponds that are still in the early stages of succession or, more often, in ponds where leaves from nearby trees and bushes cover a part of the bottom. It is often the only dragonfly present in small, largely shaded forest ponds, pools and puddles with a substrate of leaf litter, and in these situations larvae can occur in high densities. In central Europe it is also one of the most common dragonflies at garden ponds. The specie is able to resist weeks of desiccation. It has a wide altitudinal range, being mostly abundant up to 700 m but still regularly present and producing up to 1 700 m.
Distribution
The species is one of the most common and most widespread dragonflies in Europe. The core of the European range of A. cyanea is located in central and western Europe at middle latitudes, where the species is widespread and among the most common anisopterans. It does not reproduce in Ireland and is rare in Scotland. In Fennoscandia it is found in no more than the southernmost third of Finland, Sweden and Norway. It is currently expanding its range northwards. It is less common in the south of Europe, where it is largely confined to mountain areas and some Mediterranean islands (Baleares, Corsica, Sicily and Rhodes)
Flight Period
July to October, with some specimen visible in June.
Behavior
A. cyanea is a curious species and can investigate any odonatologist closely, even landing on people. It is often found in ponds in gardens and parks. If open water is created in a garden, this is often the first specie to investigate the new water.
Conservation Status
Similar Species
Aeshna viridis, Aeshna juncea
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.