Dragonfly Guide

Lestes dryas

Kirby, 1890

Emerald spreadwing

Scarce emerald damselfly

Robust spreadwing

Turlough spreadwing

Lestes dryas
Lestes dryas male, Skåne Sweden, June 2019
Photo: Jonas MyrenåsCreative Commons CCCreative Commons BYCreative Commons SA

Description

This damselfly is metallic green to bronze-green in colour with light blue pruinosity in mature adults. This species is very similar to Lestes sponsa from which it is difficult to distinguish at first sight, though L. dryas is usually more robust, especially females. In females the distinctive characters are two rectangular spots on the first abdominal segment (S1). The shape being a semi-circle in L. sponsa. The ovipositor is large and extends beyond S10 (in *L. sponsa the ovipositor does not extend beyond S10). The pronotum is metallic in colour.

Males have part of the second segment (S2) without the blue pruinosity, unlike L. sponsa which has the whole of S2 pruinose. The lower appendages have curved and enlarged tips, while being straight and narrow in L. sponsa. Rarely some females are blue like the males with blue eyes.

Teneral individuals first have a matte green colour which gives the impression of having a thin grey film covering the green. Soon the green parts become more vivid while the yellow parts become more unsaturated.

Separated from L. barbarus and L. virens by the dark underside of the head, dark pterostigma (when mature) and more extensive pruinosity. Chalcolestes parvidens and C. viridis lack pruinosity, have whitish appendages, a larger and paler pterostigma and a diagnostic thorax marking. L. macrostigma has a larger pterostigma and a darker more pruinose body with almost no hint of green.

Behaviour

Not a species to make any spectacular show and can be easily overlooked. Often it occurs in lesser numbers than similar species and numbers fluctuate a lot between years. However, it can locally be abundant. It usually emerges slightly earlier than the other Lestes species. To find it you might need to find areas where water is hardly seen between the vegetation, like in high grass or between tufts.

Distribution

Loading map...

Distribution map. Data from gbif.org

Lestes dryas is a Holarctic species occuring in both the northern part of Eurasia and North America. In Africa it is found only in the north of Morocco. It is widespread in most of Europe although it is absent from the northern parts of Fennoscandia and has a more scattered occurrence in the Mediterranean region. It is absent from most of the Mediterranean islands. It is common in the lowlands of central Europe but large populations in the south of its range are mostly found in higher altitudes.

Habitat

Lestes dryas is found at standing waters such as ponds, small lakes, bogs and occasionally gravel pits, and is mostly found in habitats with a dense growth of rushes and sedges. It favours standing waters and swamps that partially or completely dry out in the course of summer, but is also found at permanent waters that have shallow edges with rushes or grasses providing warm micro-habitat for the larvae.

Sources

  • Atlas of the European Dragonflies and Damselflies, Jean-Pierre Boudot(Editor), Vincent J Kalkman(Editor), Fons Peels(Illustrator)

  • Dragonflies and Damselflies of Europe: A scientific approach to the identification of European Odonata without capture, Galliani, C.; Scherini, R.; Piglia, A.

  • Field guide to the dragonflies of Britain and Europe, Klaas-Douwe B Dijkstra.

  • Nordens trollsländor, M. Billqvist, D. Andersson, C. Bergendorff