''Sympetrum depressiusculum'', or, the spotted darter,
is a
dragonfly
A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
from the 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. Ev ...
, distributed across
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
parts of
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
.
Description
Adults reach 29 to 34 mm in body length, of which 20–24 mm is abdomen. Males are distinguished by a flattened orange abdomen with a line of drop-shaped spots along each side and clubbed overall appearance - i.e. widest at the tip. They closely resemble males of the
ruddy darter
The ruddy darter (''Sympetrum sanguineum'') is a species of dragonfly of the family Libellulidae.
Distribution
The ruddy darter is to be found in temperate regions throughout Europepterostigma
The pterostigma (plural: pterostigmata) is a group of specialized cells in the outer insect wing, wings of insects, which are often thickened or coloured, and thus stand out from other cells. It is particularly noticeable in dragonfly, dragonfli ...
ta.
Adults fly in the late summer. They are weak fliers.
Habitat and distribution
left, Female
It breeds in temporary water bodies, which dry out in the autumn and are re-filled in late spring when the snow melts. It can also colonize reservoirs and
paddy field
A paddy field is a flooded field (agriculture), field of arable land used for growing Aquatic plant, semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in sout ...
s where such water dynamic is maintained by humans. Furthermore, it is thought to have spread across some parts of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
thanks to
carp
Carp are various species of oily freshwater fish from the family Cyprinidae, a very large group of fish native to Europe and Asia. While carp is consumed in many parts of the world, they are generally considered an invasive species in parts of ...
aquaculture which creates similar conditions.
The species is distributed across temperate parts of Eurasia from
Western Europe
Western Europe is the western region of Europe. The region's countries and territories vary depending on context.
The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the ancient Mediterranean ...
to
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, but is absent from steppes and deserts of
Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
. The majority of the European population inhabits
Alpine
Alpine may refer to any mountainous region. It may also refer to:
Places Europe
* Alps, a European mountain range
** Alpine states, which overlap with the European range
Australia
* Alpine, New South Wales, a Northern Village
* Alpine National Pa ...
slopes and lowlands of east
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
and
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...
. In the rest of the distribution range, it is only present locally. The European population is in decline due to intensification of land use and abandoning traditional agriculture, unlike populations of many other dragonfly species which have rebounded in the past few decades because of reduction in water pollution. It is thus regarded
vulnerable in Europe.
References
External links
*
{{Taxonbar, from=Q738487
Libellulidae
Odonata of Asia
Dragonflies of Europe
Insects described in 1841