Keeled Skimmer (Orthetrum coerulescens)

• English name: Keeled Skimmer
• German name: Kleiner Blaupfeil
• French name: Orthétrum bleuissant
• Dutch name: Beekoeverlibel
• Swedish name: Mindre sjötrollslända
• Norwegian name: Liten blålibelle
• Finnish name: Hoikkasinikorento
• Danish name: Lille blåpil
• Italian name: Frecciazzurra minore
• Czech name: vážka žlutoskvrnná
• Slovenian name: Mali modrač
• Bulgarian name: Бледо синилниче

Keeled Skimmer
(Orthetrum coerulescens)

Not present

Present before 1990

Present after 1990

Present before and after 1990

Present after 2015

Map data based on J.-P. Boudot & V. J. Kalkman (eds.),
Atlas of the European Dragonflies and Damselflies

General		• a fairly small species of central and especially southern Europe; absent from the far north
Classification		• suborder: Anisoptera (dragonflies); family: Libellulidae
Conservation status		• IUCN Red List Europe: Least Concern
Scientific name		• Orthetrum coerulescens (Fabricius, 1798)
Name genus		• Orthetrum: from Grk. ὀρθός = straight, parallel +; ἦτρον = abdomen ⇒ Newman described Orthetrum species as having the 'abdomen laterally parallel' (as distinct from Sympetrum species, which have the 'abdomen laterally compressed')
Name species		• coerulescens: from Lat. caerulescere, pres. part. caerulescens = becoming blue, somewhat blue ⇒ probably in reference to the increase in blue pruinescence in maturing males
Distribution		• click or tap the Map button above
Habitat		• small running waters but also lakes
Dimensions		• typical body length: 36-45 mm; hindwing: 28-33 mm
Notes		• libellulids are 'sitters': males spend a lot of time perched at the water's edge, waiting for females
		➤ noticeably smaller than O. brunneum, with which it often co-occurs in the South
		• seldom sits on the ground
		• immature animals are orange-brown
Both sexes	Wings	• for wing venation details click or tap here
Male	Head	➤ the face is beige-brown
	Thorax	➤ the thorax is unmarked brown (but may be pruinescent in the subspecies O. c. anceps)
	Abdomen	• the abdomen is entirely pruinescent light blue
Female	Thorax	• the thorax is yellow-brown with pale antehumeral stripes
	Abdomen	• the abdomen is yellow-brown with a black mid-dorsal line
		• the lower edge of S8 bulges
Photographs		• most of our photos below were made in Tuscany and the south of Italy

LineDrawing: the male's wings and the female's abdomen in dorsal view.

Orthetrum brunneum (left) and O. coerulescens (right); forewing
Note: O. brunneum typically has 5-7 doubled cells between IR₃ and Rspl. O. coerulescens typically has none.

Orthetrum brunneum (left) and O. coerulescens (right); head, male
Note: in male O. brunneum the face is whitish pale blue. In male O. coerulescens it is beige-brown.

Four Orthetrum species; abdominal segment 8, female
Note the bulging lower edge of S8 in coerulescens (top left), brunneum (top right) and chrysostigma (bottom left), but not in nitidinerve (bottom right).