''Gomphus flavipes'', the river clubtail or yellow-legged dragonfly, is a species of

dragonfly A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threat ...

in the family

Gomphidae The Gomphidae are a family of dragonflies commonly referred to as clubtails or club-tailed dragonflies. The family contains about 90 genera and 900 species found across North and South America, Europe, Asia, Australia, and Africa. The name refers ...

. It is found in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. Its natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

are

rivers A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

and large

streams A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

. The dragonfly flies from June to September depending on the location.

Geographical distribution

''Gomphus flavipes'' is a European species. It has the biggest geographical range among the European Gomphid species, occurring from

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

to eastern

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

. The species has a very patchy occurrence in Central Europe and has become rare in Western Europe. The southernmost occurrence is known from

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

. In Southern Europe ''G. flavipes'' is replaced by other Gomphid species. However, the exact geographical range of the species is still unclear.

Habitat

''Gomphus flavipes'' lives along the middle and lower reaches of slow flowing medium-sized and big rivers The species prefers riverbed with mud, clay, loam or fine sand as soil, since larvae develop buried in the soil, but avoids areas with decomposition of organic matter and oxygen-poor

stagnant water Water stagnation occurs when water stops flowing for a long period of time. Stagnant water can be a significant environmental hazard. Dangers Malaria and dengue are among the main dangers of still water, which can become a breeding ground ...

. Reaches with high drift and coarse substrate are also avoided, however, occasionally ''G. flavipes'' can be found in bigger lakes with high oxygen content.

Morphology

As a medium-sized dragonfly ''G. flavipes'' is 50–55 mm long and with an average wingspan of 70–80 mm. The eyes are widely separated, this is a typical genus-specific feature, males have blue while females have green eyes. Both sexes have predominantly yellow legs and the males has thin angled appendages, while his 10th segment is entirely black dorsally.

Behaviour and life cycle

''Gomphus flavipes'', as all dragonflies, are predators; they capture smaller insect in flight.

Imago In biology, the imago (Latin for "image") is the last stage an insect attains during its metamorphosis, its process of growth and development; it is also called the ''imaginal'' stage ("imaginal" being "imago" in adjective form), the stage in wh ...

s are rarely seen, the easiest way to observe them is in the mating period or during the emergence of young adults. Mating usually takes place in June or July. During the day adult males search for females, far from the riverbank, in low altitude above the waterfront. If they successfully catch a female copulation takes place in the shelter of water edge willows. After fertilization females fly 20–30 cm above the water and lay eggs (one at a time or in a small packets) into the water.

Larval development

The

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e develop for three years buried in the fine soil of the riverbed. As imagos, they are predators too, their diet consisting of small invertebrates which they capture with they specialized labium called the ''mask''. The emergence of the larvae starts mostly at end of May or June, but it depends highly on location and other environmental circumstances (e.g. a rainy period could delay the start of emergence). The emergence in ''G. flavipes'' is often highly synchronised and it is therefore referred as a ’summer species’, in Odonatology EM50 values are used to describe the emergence pattern (extent of synchronization). The patterns often have two peaks in ''G. flavipes'' due to the phenomenon called ’cohort splitting’. Larvae of ''G. flavipes'', unlike other

Anisoptera A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens ...

larvae, often choose riverbank soil as an emergence substrate, however the type of substrate depends on location and characteristics of the riverbank, probably the larvae have no substrate specific attachment.

Threat factors

''Gomphus flavipes'' has become an endangered species in most Western European countries due to water pollution and river regulation. The species is listed in the Annex IV of Habitats Directive.

References

External links

* {{Taxonbar, from=Q728093 Gomphidae Dragonflies of Europe Odonata of Asia Insects described in 1825 Taxa named by Toussaint de Charpentier