Red-eyed Damselfly
Erythromma najas

Yorkshire Branch
of the British Dragonfly Society

 

Status | Photos | Distribution Maps

Length: 33-37mm
Wingspan: Male 43mm; Female 46mm; Hindwing  19-24mm

Male: Mainly bronzed black with bright red eyes. Top of thorax lacking any antehumeral stripes. Segments 1, 9 and 10 are blue. Sides of thorax are blue with black line and spur present. Legs are black. Immature male is similar to female. Similar to Small Red-eyed Damselfly which is smaller, differences occur in the blue markings. At rest the wing tips reach in to segment eight, in Small Red-eyed Damselfly the wing tips only reach as far as segment 6 or 7. Generally holds its abdomen level, where as Small Red-eyed Damselfly often holds its abdomen slightly upcurved towards the end.

Female: Mainly black with green sides to thorax containing black line and spur. Segments 9 and 10 are black with narrow blue divisions. Eyes are a dull red colour. Usually have short shoulder stripes, though some lack them all together and some may form as explanation marks.

Red-eyed Damselfly

Behaviour 
Strong direct flight over water. Spend lots of time resting on broad floating leaves such as water lilies. Mats of algae and debris are also used and males may use surrounding shrubs if there is little floating vegetation. After emergence they will spend time away from water to mature. The first three weeks of emergence is probably the best time to encounter this species at close quarters. Females usually only appear at water to breed.  Copulation takes place over water or on nearby vegetation. Egg laying is mainly in tandem, both sexes often submerging. They are laid mainly on the underside of Water Lilies, though other floating vegetation will be used.

Habitat 
Large lakes, ponds, canals and slow moving waterbodies with abundant floating vegetation.

Flight Period
Nationally: Mid May to early September.
Yorkshire: Mid May to late August.

Red-eyed Damselfly Flight Period

Population Status
Species is at the northern edge of its range in Yorkshire. Current records confine it to VC61. To the east of the Wolds its is present at Tophill Low, Leven Canal and Brandesburton Ponds. To the west of the Wolds it is present on Pocklington Canal becoming more abundant to the southwestern end of the canal. It has also recently been recorded along Market Weighton Canal and several ponds in the southwest of the riding. It is possible that this species is present in the northeastern edge of VC63.

Red-eyed Damselfly Distribution

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Web Author: Paul Ashton - ©  Yorkshire Branch of the British Dragonfly Society 2005-2008 including all images unless otherwise stated.
http://www.yorkshiredragonflies.org.uk