Aeshna affinis
Aeshna affinis Vander Linden, 1820
Local names: Southern migrant hawker, Blue-eyed hawker, Südliche Mosaikjungfer, Zuidelijke glazenmaker, Æschne affine, Klarblå mosaikslända
Species Information
Description
A small hawker, similar in size to A. Mixta, which it resembles in many ways.
The males have bright blue eyes and facial suture barely marked. The thorax is yellow-brown with blue hues in mature males, and has only fine black lines along the sutures on the sides. Antehumeral stripes are short and narrow, in contrast with other species of the family Aeshnidae like A. cyanea and A. viridis. The abdomen is characterised by large light-blue spots, brighter and more extensive than on A. mixta. The second abdominal segment, S2, is all blue except for a distinctive black mask-like pattern. The pterostigma is relatively long, longer than on A. mixta. The leading wing margin, the costa, has a light colour.
Females can be very similar to males. Generally a more lightly yellow jizz compared to other Hawker females can be noted. Lighter and paler than A. mixta but can resemble Brachytron pratense in size and colour. Also, the rather uni-coloured sides of the abdomen of females make them similar to females of A. viridis. They can be distinguished from those of A. mixta by the relatively short abdominal appendages, shorter than S9-10 combined.
Size
Habitat
The species reproduces exclusively in standing waters, preferring shallow well-vegetated waters sheltered from the wind and exposed to the sun. Many habitats dry up partially or fully during the summer and have patches of mud often bordered by loose to dense vegetation of rushes, sedges, Black bogrush or low reeds. A wide selection of water types can support habitats for A. affinis, incuding marshes temporarily flooded depressions in agricultural landscapes, old oxbows, small (dune) lakes and ponds or shallow edges of larger lakes with helophytes belts. Despite of the broad array of habitats, suitable habitats are generally scarce. Many of the habitats where A. affinis occurs become unsuitable after several decades or even a few years due to natural succession of vegetation, for example, following inundation of floodplains. In other situations, management such as grazing or mowing is needed to maintain suitable habitat. In contrast with other species with a strong preference for warm climatic conditions, it is rarely found in quarries or gravel pits. In Italy it is also found in rice fields, but it has decreased in this habitat.
Aeshna Affinis is mainly found in lowlands and in central Europe it is seldom found above 700 m.
Distribution
A largely Western Palaearctic specie, confined to north-west Africa, Europe and south-western Asia. In Europe it is widespread in southern Europe and parts of central Europe, becoming scarcer to the north. It is relatively uncommon in many areas, including lerge parts of the Iberian peninsula, and to a lesser extent, Italy. It is common in much of south-east Europe and locally abundant i Ukraine.
Flight Period
May to August
Behavior
This species is a powerfull flyer and often migrates from the southernmost areas of Europe far up to the north in good years. The male usually incessantly patrols its territory, flying low at about chest height, often beating back and forth over a small area. It frequently perches and alights on tall grass and bushes. It's not easily disturbed. It is the only species of the hawkers in which the male stays attached to the female after mating, laying eggs in tandem.
Conservation Status
Similar Species
Aeshna mixta, Aeshna viridis (females)
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.