Aeshna grandis
Aeshna grandis (Linnaeus, 1758)
Local names: Brown hawker, Braune Mosaikjungfer, Bruine glazenmaker, Grande æschne, Brun mosaikslända
Species Information
Description
Aeshna grandis is a large dragonfly. The general colour is brown, even the eyes are brown with a yellow back liner. The wings are evenly tinted with a bronze shade, which is visible in flight. Mature males have blue spots beside the base of each wing, on S2 and the side of the abdomen. They also get a blue hue in their eyes. Females have blue spots only beside the base of the wings, the other spots are yellow. In immature individuals, all spots are yellow. A. grandis has none or indistinct antehumeral stripes. The thorax sides has two broad lemmon-yellow bands, with no spots in between.
Size
Habitat
Found near all types of standing or, less often, slowly flowing waters, such as peaty ponds, lakes, canals, oxbows, peat bogs and fenlands, and to a lesser extent water storage facilities, ditches and manmade peat excavations.
Habitats mostly have several characteristics in common, typically being situated in forest areas and fringed by a belt of helophytes or peat moss, or having a dense floating or submerged vegetation. In the south of its European range, the species is absent from habitats in the early stages of succession, apparently requiring more mature habitats. Most of the population in central and northern Europe are found in lowlands up to 500 m in altitude, but in the west and the south of its range long-lasting populations are confined to higher altitudes, although in the Alps most populations are found below 1 000 m. Nevertheless, it's frequently found up to 2 00 m in Austria and the French Pyrenees and reproduction has been recorded up to 2 250 m.
Distribution
Widespread in northern, central and easter Europe with a continuous range reaching the Massif central in France, the Alps and the mountains of Romania. In the French Pyrenees and south-east Europe populations are small and isolated. In the west and south it prefers forested areas and might be lacking in open landscapes, like central Hungary. In central Europe it is common, but population levels are usually low compared to other more abundant aeshnids.
Far higher densities are found in mountainous areas and in the north and north-east, where it can be omnipresent.
Flight Period
July to Septembr
Behavior
Flight is powerful, fast and untiring. Males patrol large areas. Males might seem less aggressive than other aeshnids but that might be due to territorial size rather than any male backing down on a fight. It will still engage on any other male they meet. It can be found in numbers, ten or more, far from waters, hunting high up in the air in glades, on forest road openings or over tree-tops. On warm summer evenings it can be active quite late in the evenings.
Conservation Status
Similar Species
Isoaeshna isoceles
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.