11
total number of species present in the County
has declined very little in the course of the
century.
This net figure is, however, rather misleading.
Certainly two species appear to have been lost
since 1953. Of these the Black Sympetrum
(Sympetrum danae) appears to have been always
confined to the Epping Forest area. Thorough
searches there and elsewhere in the County have
so far failed to yield any reliable sightings of
it in recent years. The other, the Dainty
Coenagrion (Coenagrion scitulum) was discovered
in its only known British site, in South Essex,
by Cynthia Longfield and E.B. Pinniger in 1946.
It is believed to have become extinct as a result
of flooding in 1953. Some partial consolation
is to be gained from the apparent recolonisation
of the county by the Variable Coenagrion
(Coenagrion pulchellum) and a few recent
sightings of the so-called common Hawker (Aeshna
juncea). But no consolation is to be gained from
what is almost certainly a drastic decline in
overall dragonfly populations in Essex, even if
numbers of species have remained surprisingly
constant. Two species formerly of secure
breeding status (Brachytron pratense and
Cordulegaster boltonii) have exceedingly few recent
records, and may, indeed, no longer be with us.
Aeshna juncea appears to be an occasional
'wanderer' into our county, rather than an
established breeding species, whereas Coenagrion
pulchellum has only one currently well-
authenticated breeding site in the county. A
further species, Platycnemis pennipes (the White-
legged damselfly), has also probably declined
significantly in Essex as it has nationally.
This very beautiful damselfly is very sensitive
to pollution in the slow-moving rivers which
it inhabits, and appears to require a rich aquatic,
emergent and marginal flora in its sites. It