Orthetrum coerulescens (Fabricius, 1798)
Common name: Keeled Skimmer
Preferred environment: flushes and gentle flowing streams in bogs, heaths and fens. Rarely in still water. Many Irish sites are on warm south facing slopes.
Flight period: mid May to the end of September, late June to mid August in northern parts of range. Mid June to beginning of September in Ireland.
Adult habitat and habits: Mature adults occur close to breeding sites. males defend small area around prominent perch against rivals. If female is encountered , copulation is attempted. Pair mate on ground.
Oviposition site and behaviour: females lay eggs alone and usually with male in attendance, by dipping abdomen on water surface and releasing batch of eggs.
Larval habitat and habits: larvae are found amongst debris in flushes and runnels. Larval development takes two years.
Emergence behaviour: emergence happens from early morning.
Range: southern and western Europe. Very local in northern Europe to southernmost Fennoscandia. Eastern limits unclear, but reaches Black Sea in Romania and Crete. In Ireland confined to mountain regions, especially in Kerry, Wicklow, Galway and Mayo. Very local in north and north east confined to just a few locations in Donegal and Down. Species is absent from central plain.
Determination of adults: species is keyed in Askew (1988) which figures diagnostic characters of both sexes.
Determination of larvae: keys to mature larvae in Askew (1988) and Brooks (1997).
|Nelson, B., Thompson, R. & Morrow, C., 2000 (May 2). [In] DragonflyIreland http://www.ulstermuseum.org.uk/dragonflyireland/|