Chalcolestes viridis

Chalcolestes viridis, formerly Lestes viridis, is a damselfly of the family Lestidae. It has a metallic green body and at rest it holds its wings away from its body. Its common name is the willow emerald damselfly or the western willow spreadwing. The genus Chalcolestes is separated from Lestes because of differences in their larvae. A closely related species C. parvidens used to be considered a sub-species of C. viridis. C. parvidens occurs in Greece, Bulgaria, Croatia and in Italy; near Rome it flies with C. viridis in the same ponds. There are small morphological differences between the two species both as adults and larvae and analysis of proteins from the two species, by electrophoresis, also supports their separation into two species, but they are hard to tell apart in the field. C. parvidens flies earlier in the year than C. viridis. C. viridis is found across southern and central Europe. In the eastern mediterranean it is replaced by C. parvidens with areas of overlap in Italy and the Balkans. C. viridis is found on many mediterranean islands including Corsica, Sicily, Mallorca, Menorca and Ibiza, in the Maghreb in North Africa, Turkey and the Middle East. However many of the old records for C. viridis in the east of its range could be for C. parvidens. It occurs in still or slow flowing water in ditches, ponds, lakes and canals, with overhanging willows, alders or birches, which are used for breeding. Of all the European Lestes it is the species, along with C. parvidens, that will lay eggs in where there is running water. The adults are often found in the bushes which grow over or alongside water. In Britain it was a rare vagrant and is now a new colonist. It is widespread on Jersey. In the field it is not possible to reliably distinguish C. viridis from C. parvidens. Both species are mainly metallic green, like other Lestes damselflies, but larger and darker but they do not have a powder blue pruinescence which is common in other Lestes. The pterostigma is pale brown and outlined in black. The thorax has thin yellow antehumerals and broader yellow stripe above a thin black line on each side; the upper edge of the stripe is irregular. Both C. viridis and C. parvidens have a prominent spur-like marking on the side of the thorax. Male - The abdomen is very long. The lower anal appendages are less than half the length of the upper which are a distinctive pale yellow with black tips. Female - The ovipositor is longer than in Lestes dryas.