This species has the uncharacteristic habit for a damselfly of resting with its wings outstretched, typically in a half-open position. It is very hard to distinguish from its relative, the Scarce Emerald (Lestes dryas). Males are largely metallic green, but the tip and base of the abdomen are pale blue. Females are a duller green and lack the pale blue segments.
National status
Locally common throughout Britain.
Status in Sussex
Scattered across the county, with concentrations on Pevensey Levels, Romney Marsh and Ashdown Forest. During the two decades to 2020, the number of records from these strongholds appear to have reduced. This may be due to less recording but there is some indication that there has been contraction in its range in the Low Weald during this time. Chelmick (1979) referred to a “marked preference for sandstone regions and presumably more acid waters”. The maps show a broader, albeit scattered and patchy distribution. Due to its apparent decline, all records would be of interest.
Distribution at 1km scale
Historical records
It appears that this species has always had a widespread distribution, and map in the Dragonflies of Sussex (2004) shows a similar pattern to that of Chelmick (1979), though with additional sites and a wider range of habitats.
Flight times
Mid June - mid September. There appears to have been an expansion in the flight times from late to mid June during the two decades up to 2020.
Phenology (adult)
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Emerald Damselfly habitat at Lavender Platt on the edge of Ashdown Forest Photo: Simon Linington
Habitat
A wide range of shallow, standing waters, from acid heathland bogs to canals, ponds and lakesides, as long as there is plenty of aquatic and marginal vegetation. It also tolerates fairly brackish sites.
Conservation
The best Sussex sites contain plenty of submerged and floating vegetation. Since fish are major predators, the larvae need sufficient plant cover or, preferably, water bodies without fish in them. The adults usually mate amongst lush vegetation cover around water; the female, sometimes completely submerged, inserts her eggs into plant stems. The patchy distribution is at least partly explained by such specialist habitat requirements, which could be easily destroyed through excessive clearance or dredging.
All four Emerald Damselflies have the uncharacteristic damselfly habit of resting with their wings outstretched in a half open position (more like a dragonfly). Willow Emerald is a newly-colonising species in Sussex while the Southern Emerald and Scarce Emerald are both currently very rare migrants though this status may change as a result of climate change.
The Emerald Damselfly has a rich metallic green colour and the male develops a blue pruinescence on both ends of the abdomen (segments 1, 2, 9 and 10) as it matures. The female is thicker bodied than the male with no blue pruinescence and a metallic and almost plain coloration. It also has a distinct dark spot above the middle leg. The pterostigma (coloured wing-spots on the leading edge of the wing) are dark brown. It has this in common with the Scarce Emerald which can be distinguished from the commoner Emerald by the less extensive pruinescence on the mature male, and the curved rather than straight anal appendages. The female has square dark spots on abdominal segment 1 rather than rounded as in the Emerald (though this is difficult to see in the field), and an ovipositor that extends just beyond the tip of the abdomen.
The Willow Emerald Damselfly is slightly larger than the other Emerald species and both sexes are a dark metallic (almost bronze) green. Importantly, it has pale brown pterostigma bordered dark. It also has a prominent dark ‘spur’ on the side of the thorax. It has different habitat preferences to Emerald and favours waterside trees. The Southern Emerald Damselfly is also metallic green and can be identified by its bicoloured pterostigma and broad pale antehumeral stripes over the thorax.
This species has the uncharacteristic habit for a damselfly of resting with its wings outstretched, typically in a half-open position. It is very hard to distinguish from its relative, the Scarce Emerald (Lestes dryas). Males are largely metallic green, but the tip and base of the abdomen are pale blue. Females are a duller green and lack the pale blue segments.
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Adult female Photo: David Sadler
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Adult male Photo: Simon Linington
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Pair in tandem Photo: Simon Linington
National status
Locally common throughout Britain.
Status in Sussex
Scattered across the county, with concentrations on Pevensey Levels, Romney Marsh and Ashdown Forest. During the two decades to 2020, the number of records from these strongholds appear to have reduced. This may be due to less recording but there is some indication that there has been contraction in its range in the Low Weald during this time. Chelmick (1979) referred to a “marked preference for sandstone regions and presumably more acid waters”. The maps show a broader, albeit scattered and patchy distribution. Due to its apparent decline, all records would be of interest.
Distribution at 1km scale
Historical records
It appears that this species has always had a widespread distribution, and map in the Dragonflies of Sussex (2004) shows a similar pattern to that of Chelmick (1979), though with additional sites and a wider range of habitats.
Flight times
Mid June - mid September. There appears to have been an expansion in the flight times from late to mid June during the two decades up to 2020.
Phenology (adult)
1 / 1
Emerald Damselfly habitat at Lavender Platt on the edge of Ashdown Forest Photo: Simon Linington
Habitat
A wide range of shallow, standing waters, from acid heathland bogs to canals, ponds and lakesides, as long as there is plenty of aquatic and marginal vegetation. It also tolerates fairly brackish sites.
Conservation
The best Sussex sites contain plenty of submerged and floating vegetation. Since fish are major predators, the larvae need sufficient plant cover or, preferably, water bodies without fish in them. The adults usually mate amongst lush vegetation cover around water; the female, sometimes completely submerged, inserts her eggs into plant stems. The patchy distribution is at least partly explained by such specialist habitat requirements, which could be easily destroyed through excessive clearance or dredging.
All four Emerald Damselflies have the uncharacteristic damselfly habit of resting with their wings outstretched in a half open position (more like a dragonfly). Willow Emerald is a newly-colonising species in Sussex while the Southern Emerald and Scarce Emerald are both currently very rare migrants though this status may change as a result of climate change.
The Emerald Damselfly has a rich metallic green colour and the male develops a blue pruinescence on both ends of the abdomen (segments 1, 2, 9 and 10) as it matures. The female is thicker bodied than the male with no blue pruinescence and a metallic and almost plain coloration. It also has a distinct dark spot above the middle leg. The pterostigma (coloured wing-spots on the leading edge of the wing) are dark brown. It has this in common with the Scarce Emerald which can be distinguished from the commoner Emerald by the less extensive pruinescence on the mature male, and the curved rather than straight anal appendages. The female has square dark spots on abdominal segment 1 rather than rounded as in the Emerald (though this is difficult to see in the field), and an ovipositor that extends just beyond the tip of the abdomen.
The Willow Emerald Damselfly is slightly larger than the other Emerald species and both sexes are a dark metallic (almost bronze) green. Importantly, it has pale brown pterostigma bordered dark. It also has a prominent dark ‘spur’ on the side of the thorax. It has different habitat preferences to Emerald and favours waterside trees. The Southern Emerald Damselfly is also metallic green and can be identified by its bicoloured pterostigma and broad pale antehumeral stripes over the thorax.
