Fen Bog – Page 2 – Yorkshire Dragonfly Group

Keeled Skimmer Orthetrum coerulescens

Posted on 22 April 1982 by Paul Ashton

Length

36-46mm; Wingspan: Male 57-63mm; Hindwing 28-34mm; Larva: 17-23mm

Males

Dark brown thorax with buff antehumeral stripes, which fade with age. When mature the abdomen is blue, except S1. Blue grey eyes. Wings have a yellow tint when immature which clear as they mature. Pale yellow costa and orange pterostigma. Blue grey eyes.

Females

Dark brown thorax with buff antehumeral stripes. The abdomen is a yellow/brown colour with a thin dark keel line down the centre. Pale yellow costa and orange pterostigma.

Behavior

Males have small territories observing them from the ground or low perches. Copulation occurs on the ground and can last anything from 2-60 minutes. Flight is fast and erratic with brief spells of hovering. Wings are held well forward when at rest. Females spend a lot of time resting in vegetation not far from water.

Habitat

Acidic wet heath and peaty moorland sites typically with sphagnum mosses, frequents pools, runnels and streams.

Flight Period

Status

Confined to VC62 where it appears to be present in suitable sites surrounding Fylingdales Moor. Several records of dispersing individuals.

Distribution Map

Locations

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Common Darter Sympetrum striolatum

Posted on 22 April 1981 by Paul Ashton

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Length

37mm, Wings 57mm.

Males

Thorax brown with yellow patches on sides; abdomen orange/red with black central line last 2 segments ; legs black/yellow; eyes brownish; black line on top of the frons only.

Females

Thorax pale brown with yellow side panels; abdomen yellow with black central line segments 9-10 and along sides. Old females tend to take on male colours.

Habitat

Preferences are quite catholic, including ponds, lakes, canals, ditches and slow-flowing rivers. It is tolerant of brackish conditions and peaty bog pools. Can be found away from breeding sites feeding in sheltered locations, like woodland rides and hedgerows.

Behavior

Males are territorial, spending a lot of time perched, only making short flights when disturbed or chasing off intruders. Basks on the ground, especially late in the season when temperatures are lower. Frequently found away from water in sheltered areas, especially females wanting to avoid attention from males. Copulation takes place at rest, lasting around 10-15 minutes. Oviposition regularly takes place in tandem, where the eggs are flicked into the water by dipping the abdomen onto the surface. Females will also oviposit alone. Larvae emerge after one year, this taking place during the morning, onto bare bank sides or emergent vegetation.

Flight Period

Distribution Map

Locations

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Black Darter Sympetrum danae

Posted on 22 April 1977 by Paul Ashton

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Length

32mm, Wings 47mm

Males

Narrow waist on black abdomen with golden spots segment 1 and 2, 8 and 9; thorax 2 yellow bars on side, 1 of black panels has 3 yellow spots; legs black.

Females

Yellow with black triangle top of thorax; legs black.

Behaviour

Males are not very territorial, with large numbers being present at some sites. Males hover over emergent vegetation, seeking females to mate with. They will frequently settle, especially on open ground and stones. In hot weather they will rest in the obelisk position, with abdomen pointing upwards, to reduce the surface area presented to the sun. Copulation lasts for several minutes, with oviposition taking place in tandem or alone. Oviposition takes place either directly into water, or into mud and mats of vegetation. Larvae emerge after one year and can survive the temporary drying out of their habitat.

Habitat

Mainly heaths containing boggy pools, peaty ponds and lakes with abundant emergent rushes and sedges. Sheltered sites produce the highest numbers. Sometimes disperses into atypical locations.

Flight Period

Distribution Map

Locations

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