The Irish Damselfly or Crescent Bluet (Coenagrion lunulatum) is a damselfly

Damselfly

Damselflies are insects in the order Odonata. Damselflies are similar to dragonflies, but the adults can be distinguished by the fact that the wings of most damselflies are held along, and parallel to, the body when at rest...

 found in northern Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

; outside northern Finland

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 the species is rare. It is also scarce and local in the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

 and Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. One of its English name comes from the fact that it is found in Ireland but not in Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

. The alternative name, Crescent Bluet, refers to the shape of the markings on segment two of the male and its scientific name.

Appearance

This species is similar to the Azure Damselfly

Azure Damselfly

The Azure Damselfly is a species of damselfly found in most of Europe. It is notable for its distinctive black and blue colouring.-Males:...

 (Coenagrion puella), the Variable Damselfly

Variable Damselfly

Coenagrion pulchellum, the Variable Damselfly or Variable Bluet, is a European damselfly. Despite its name, it is not the only blue damselfly prone to variable patterning....

 (Coenagrion pulchellum) and the Common Blue Damselfly

Common Blue Damselfly

The Common Blue Damselfly or Northern Bluet is a European damselfly.The species can reach a length of 32 to 35 mm...

 (Enallagma cyathigerum) with which it coexists. However, both the female and male are darker and shorter-bodied in comparison with other blue damselflies.

The species can be identified using the following features:

• In males the back of the abdomen is mostly black, whilst segments 8 and 9 are all blue.

In males the underside is bright green especially on the head and thorax (see side view)

• The blue is of a darker shade than similar species
• Females are dull green with black markings
• In females the hind margin of the pronotum has a prominent raised point (see comparison of pronotums of blue damselflies)

Status in Ireland

In Ireland, the species is uncommon, and confined to the midlands and north. It is listed as Vulnerable on the Red List of Irish dragonflies. Adults have been recorded from the beinning of May (Adults seen in Co Tyrone on 1st May 2011) to late July. It is found on sheltered mesotrophic lakes and large pools, fen

Fen

A fen is a type of wetland fed by mineral-rich surface water or groundwater. Fens are characterised by their water chemistry, which is neutral or alkaline, with relatively high dissolved mineral levels but few other plant nutrients...

s and cutover bog

Bog

A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....

s.

It was first recorded in Ireland in Sligo

Sligo

Sligo is the county town of County Sligo in Ireland. The town is a borough and has a charter and a town mayor. It is sometimes referred to as a city, and sometimes as a town, and is the second largest urban area in Connacht...

 in 1981; in total, it has been recorded from approximately 40 sites in 13 counties. The majority of sites have been in counties Fermanagh, Tyrone

Tyrone

The name Tyrone can refer to:*County Tyrone, a county in Northern Ireland, roughly corresponding to the ancient kingdom of Tír Eogain*An Earl of Tyrone*A small steam train which runs between Bushmills and the Giant's Causeway in Northern Ireland-Places:...

, Armagh

County Armagh

-History:Ancient Armagh was the territory of the Ulaid before the fourth century AD. It was ruled by the Red Branch, whose capital was Emain Macha near Armagh. The site, and subsequently the city, were named after the goddess Macha...

 and Monaghan

County Monaghan

County Monaghan is a county in Ireland. It is part of the Border Region and is also located in the province of Ulster. It is named after the town of Monaghan. Monaghan County Council is the local authority for the county...

. One of the places it has been successfully recorded and photographed is Brackagh Moss Bog, in Armagh.

Eutrophication

Eutrophication

Eutrophication or more precisely hypertrophication, is the movement of a body of water′s trophic status in the direction of increasing plant biomass, by the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system...

is suggested as the most serious threat to the species.