Brachythemis impartita
Brachythemis impartita (Karsch, 1890)
Local names: Northern banded groundling, Treuer Kurzpfeil, Bandgrondlibel
Species Information
Description
This dragonfly is common in Africa but also present in some parts of Europe. It is rather small, about the size of Sympetrum sanguineum, but more robust.
The males can easily be identified by the dark body, almost black, and the dark bands crossing the wings between node and pterostigma. In both sexes, the pterostigma is rather long, whitish in colour with the outer end dark. The legs are yellowish with black lines. The females are sandy coloured with dark line on the thorax, the abdomen has a black carina (a keel-like ridge along the upper side) and blackish lines on the side of each segment. The eyes are grey on the lower part and light brown on the upper part with dark crosswise striations. Unlike the males, usually the females have hyaline wings. The immature males have a colour similar to that of the females and also lack the bands on the wings. In fact, the latter are not present at the emergence but appear and gradually darken during the maturation, like the rest of the body, eyes included. At times, even the old females have the wing bands, but in any event they are lighter in colour than those of the males.
Only Sympetrum pedemontanum has similar bands on the wings but different in colour and closer to the pterostigma. However, the species are immediately distinguishable since the females of S. pedemontanum are bright yellow and the males are red with pterostigmas also red. Furthermore, the two species are not knowing to overlap.
In Turkey, immature individuals can be similar to Brachythemis fuscopalita, but that species has uniformly coloured pterostigma.
Size
Habitat
Brachythemis impartita breeds in a wide range of stagnant water bodies with a preference for large lakes. Many European populations established on large manmade barrage lakes. the species is also found onslow flowing rivers. Preferred habitats have open water with varying level and are surrounded by gentle sloping and fully sun-exposed dirt banks with little or no vegetation. The species often occurs in high densities and shows nomadic behaviour, resulting in a readily colonisation of newly created water bodies and in records of vagrants outside of its breeding range.
Distribution
Brachythemis impartita is a newcomer to Europe, being first recorded in Portugal in 1957. Further findings remained rare until the beginning of the eighties, with first records in Spain in 1961, Sardinia 1979 and Sicily in 1980. Since then, the species has expanded to Cyprus and Corsica. At present, it is locally common in southern Sicily, Sardinia and the south-west of the Iberian Peninsula. Scattered records are known from central and eastern parts of Spain. Densities can be locally very high and the species is, for example, the most common summer dragonfly on Sardinia. Over 10 000 adults were recently seen along several hundred meters of the shoreline of a Portuguese barrage dam and the lake itself was estimated to be home to millions of individuals. For Cyprus there is only one record of three individuals observed in August 2006 and it is unclear if the species has established on the island.
Flight Period
April to October
Behavior
In Africa this species is commonly found at waterholes fluttering in the footsteps of big game. Prefers to fly over and to perch on bare ground, frequently following large mammals, such as cattle or humans, probably to prey on disturbed insects. Often found in dense aggregations in the shade during midday heat.
Conservation Status
Similar Species
Sympetrum pedemontanum
External Links
Genus: Brachythemis
Brachythemis is a genus of dragonflies in the family Libellulidae. They are commonly known as groundlings.
Identification
Small, thickset libellulids. Their abdomen is without waist or club. Females and young males are beige, with fine, intricate and often smudgy dark markings. Often with diagnostic dark transverse bars on top of the eyes. The wings are clear or marked with dark patches. The pterostigmas are (largely) cream-coloured. Mature males become wholly blackish, with large dark wing patches. In contrast, the pterostigmas remain pale. The combination of three rows of cells immediately distal to the triangle and the absence of cross-veins in the triangles (and often subtriangles) excludes all other libellulidgenera, while only Acisoma and Pantala share a transverse ridge near the base of S4 (similar to that on S3). The female's appendages are notably long and claw-like.
Separation from other genera
Mature males can be confused only with other libellulids with patterned wings, such as Sympetrum pedemontanum or Rhyothemis semihyalina, although these differ widely in shape, behaviour, range and coloration. Females and young males (with unmarked wings) may resemble Sympetrum, Orthetrum and Trithemis, but are separated by their (largely) whitish pterostigmas. Only very recently-emerged individuals of the other genera still have white pterostigmas.
Separation of the species
Five species inhabit the warm parts of the Old World; one extends into Europe from Africa, another from Asia. The two may meet in Turkey, where they are easily separated by pterostigma colour in both sexes, and wing pattern in males.
Family: Libellulidae
The skimmers or perchers and their relatives form the Libellulidae, the largest dragonfly family in the world. It is sometimes considered to contain the Corduliidae as the subfamily Corduliinae and the Macromiidae as the subfamily Macromiinae. Even if these are excluded, there still remains a family of over 1000 species. With nearly worldwide distribution, these are almost certainly the most often seen of all dragonflies.
The genus Libellula is mostly New World, but also has one of the few endangered odonates from Japan: Libellula angelina. Many of the members of this genus are brightly colored or have banded wings. The related genus Plathemis includes the whitetails. The genus Celithemis contains several brightly marked species in the southern United States. Members of the genus Sympetrum are called darters (or meadowhawks in North America) and are found throughout most of the world, except Australia. Several Southern Hemisphere species in the genera Trithemis and Zenithoptera are especially beautiful. Other common genera include Tramea and Pantala.
The libellulids have stout-bodied larvae with the lower lip or labium developed into a mask over the lower part of the face.
The family name may have been derived from the Latin libella which means booklet.