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Status and distribution
Coenagrion pulchellum (Vander Linden) Variable damselfly
Description The identification of C. pulchellum, as with most other species in this genus,
requires careful examination. Males are blue with black markings. The blue
antehumeral stripes are narrow and often reduced to a pair of ! marks. The
black mark on segment 2 of the abdomen is typically stalked and usually much
thicker than in male C. puella, which this species resembles. Sometimes,
however, this stalk is absent. The black mark on the dorsal surface of segment
9 is nearly always more extensive than on C. puella. The shape of the anal
appendages is diagnostic. There are two female forms: one is dark with
greenish yellow markings on the sides of the thorax and abdomen, and the
other is a blue form in which the black markings on the dorsal surface of the
abdomen are more extensive than in the male, and in which the black mark on
abdominal segment 2 superficially resembles male C. merculiale, being
thistle-shaped. This form is almost identical to a blue female form of C. puella,
but female C. pulchellum can be separated from both these species by the trilobed
posterior margin of the pronotum.
European and world
distribution
Habitat C. pulchellum breeds in fens, mesotrophic ponds and lakes, slow-flowing
dykes in coastal levels, canals and peaty pools and ditches in cut-over bogs. It
is probably more dependent on emergent vegetation than C. puella.
Breeding biology C. pulchellum does not appear to be territorial and it can occur at high
densities. Copulation takes 10-15 minutes, and the eggs are inserted into the
stems or leaves of aquatic plants such as pondweeds, water-lilies or the
floating remains of rushes and common reed, while in tandem. The larvae
probably take one year to develop.
Flight periods Adults are on the wing from mid-May to the beginning of August. In Britain
and Ireland they are often seen with dragonflies such as Brachytron pratense
and Sympetrum sanguineum, as well as the commoner damselflies including
C. puella. However, in Ireland, C. pulchellum appears to be more tolerant of
acidic conditions and can be found with Aeshna juncea and Lestes sponsa on
peaty moorland pools at moderately low altitudes. Where C. pulchellum and
C. puella co-exist in Ireland, C. pulchellum is usually much the commoner.
In Britain, C. pulchellum is found most commonly on the coastal marshes and
levels of Somerset, Sussex and Kent, in Norfolk and the Fens, in the fens of
Anglesey and in south Galloway. Elsewhere it is quite a scarce damselfly, and
has declined in many areas of eastern England due to intensive agricultural
pressures. In areas such as Romney Marsh, Kent, and in the Fens, this decline
has been caused mainly by the conversion of grazing marshes to arable land,
with the consequent lowering of the water table and loss of traditional dyke
management techniques. C. pulchellum was recently rediscovered at several
locations in west Scotland along with, appropriately, B. pratense (Smith & Smith
1984). C. pulchellum occurs extensively throughout the fens and peatlands of
the Irish midlands, and is commonly found in Co Fermanagh, south Tyrone and
the Lough Neagh area. It is probable that future surveys will link these two
distribution areas. C. pulchellum is not uncommon in western districts of Co
Cork, Co Kerry and Co Galway Elsewhere it has a scattered distribution that
needs clarification by further fieldwork.
C. pulchellum has a slightly more northerly distribution in Europe than C.
puella, being absent from much of the Iberian peninsula and Mediterranean
islands, and it is found further north in Scandinavia. Its range extends to west
Asia.
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