The southern damselfly, Coenagrion mercuriale (Chapentier), is one of five members of the genus Coenagrion currently found in Britain. This genus constitutes the 'blue damselflies' that are all blue and black in colouration, and of which C. mercuriale is the smallest.
The southern damselfly enjoys individual species protection within Europe as a whole, and several European countries (including Britain) have taken complementary legislative measures for protection at a national or regional level.
C. mercuriale is restricted in distribution at both a global and national level. It is limited to the south and west of Europe and has populations of unknown status in northern Africa. Populations in Italy and northern Africa consist of different sub-species to other European populations. It has disappeared or is on the edge of extinction in seven European countries along the northern boundaries of its distribution (Austria, Belgium, Luxembourg, Netherlands, Poland, Romania and Slovenia) and is declining in three others (Britain, Germany and Switzerland) (Grand 1996).
C. mercuriale is on the northern
edge of its range in Britain and has a discontinuous distribution, restricted
mainly to the south and west of the country. Major strongholds of populations
are found on heathlands in the New Forest in Hampshire and the Preseli
hills in Pembrokeshire, with scattered populations in Devon, Dorset and
Gower, and single populations in Anglesey and Oxfordshire. There are also
large centres of population in water meadow ditch systems surrounding
the River Itchen and to a lesser extent the Test. It has disappeared from
Cornwall, has declined in Devon and Dorset and has been lost from St.
David's Peninsula in Pembrokeshire. Although the two habitat types in
which C. mercuriale is found in Britain, heathland streams/valley
mires and water meadow ditch systems surrounding chalk streams, seem different
at first sight, there are actually many similarities for the ecological
requirements of the species.
Ecology of the Southern Damselfly
Monitoring the Southern Damselfly
