|Urothemis is a genus of dragonfly
in family Libellulidae. Species occur from Africa, across Asia to Indonesia
and Australia. The genus contains the following species:
Urothemis abbotti (Laidlaw, 1927)
Urothemis aliena (Selys, 1878) - Red Baron
Urothemis assignata (Selys, 1872) - Red Basker
Urothemis bisignata (Brauer, 1868)
Urothemis consignata (Selys, 1897)
Urothemis edwardsii (Selys, 1849) - Blue Basker
Urothemis luciana (Balinsky, 1961) - St Lucia Basker
Urothemis signata (Rambur, 1842)
Urothemis thomasi (Longfield, 1932)
Urothemis edwardsii (Selys, 1849),
the Blue Basker, is a stout, medium-sized dragonfly. With length 40 - 42
mm, hindwing length 33.5 - 35 mm, it is an attractive species with deep
blue and black markings. The blue colouration of the male's abdomen is
overlain with a distinctive ladder-like pattern of black along the upper
surface. The blue basker's head is shiny black with light grey patches
in places, and the eyes are generally black. Its hindwings are marked at
the base with a black to purplish patch, which is outlined with an amber
halo. The pterostigmas (the dark coloured cells near the tip of the wings)
are light yellowish with a thin, black margin along the front edge.
Although similar in size to the male,
the female blue basker differs in colour. Instead of blue, the female is
light yellow to greyish-brown, overlain with dark brown markings. The hindwing
patch is much less intensely coloured than in the male, and the wing tips
of the female are also marked with dark amber
A freshwater species, the blue basker
can be found in or around reedy pools, marshes and lakes, as well as slow
flowing, almost stagnant, streams, rivers and floodplains. It can also
occasionally be found in grasslands, and may also sporadically colonise
high-elevation pools if conditions are suitable.
Urothemis edwardsii edwardsii (Selys, 1849)
Urothemis edwardsii hulae (Dumont, 1975)
Widespread in tropical Africa, Urothemis
edwardsii mainly occurs south of the Sahara. Its western range includes
Mauritania, Senegal, Gambia and Sierra Leone, extending eastwards to Egypt,
Sudan and Somalia. The southern extent of its range includes South Africa.
A relict population of the blue basker exists in North Africa, in the north
of Algeria. It also occurs in the Middle East, including Arabia and Oman.
This species was previously found in Palestine, where it is now believed
to be extinct.
In view of its wide distribution,
and because it is unlikely to be declining fast enough to qualify for listing
in a threatened category, Urothemis edwardsii is classified as Least Concern
(LC) on the IUCN Red List, but it is accessed as Critically Endangered
(CR) on the IUCN Mediterranean Red List.