recent discoveries are within a few kilometres of those older sites. These newer colonies
may well have become established as older ones died out whilst the presence of the
species remained undetected. As far as the north-east Essex sites are concerned, these
are outside the traditionally known range of the species and it is possible that the species
was here all along, undetected.
Finally, a word about conservation. Given the dependence of the species on shallow
ditches and pools with plentiful emergent vegetation, large scale mechanical clearance
of borrow dykes and ditches would clearly be a serious menace. A degree of
brackishness in the water seems to be tolerable, but what is currently unknown is the
extent to which survival of the species is threatened by various types of agricultural
activity. Lightly grazed grassland and hay meadows are clearly suitable for the species
although it has been found in roadside ditches and in ditches on arable land. What is as
yet unclear is whether these latter sightings represent genuinely self-sufficient breeding
colonies, or simply 'wanderers' from larger breeding populations in more suitable
habitat.
Platycnemis pennipes (Pallas, 1771) White-Legged Damselfly
This species is immediately distinguishable from the other predominantly blue (or
black and blue) damselflies by the very pale blue of even fully mature males. The
flattened, feather-like hind tibiae (to which the English name refers) are also quite
distinctive at close quarters. The females have much reduced black markings compared
with the males, and typically they have a pale green background colouration. Both sexes
are creamy white on emergence. The flight-period recorded for the species in Essex
from 1980 to 1987 was from the last week in May through to mid-August.
Historically, the species seems to have been always highly localised in Essex.
Doubleday (1871) reported it as 'common over small streams' in the Epping district,
whilst W. J. Lucas (1900) added a more recent record by C. A. Briggs for Epping, and also
gave the River Lee in Middlesex as a locality for it. No new reports of the species were
given by Harwood (1903), and the species did not appear in the various Forest reports
written by the Campion brothers, nor in Hammond's unpublished notes on his Forest
visits. However, the species did occur on E. E. Syms' list and E. B. Pinniger reported a
singleton of the species in the Forest in 1932 (Pinniger, 1933). Outside Epping Forest, the
species was reported from the River Stour near Bures by J. E. H. Roberts (Lucas, 1927),
from the River Roding in 1934 (Pinniger. 1935) and again as 'abundant' on the Roding
between Abridge and Chigwell in 1936 (Pinniger, 1937). C. Longfield (1949 b) gave the
Roding as the Essex stronghold for P. pennipes, but said it was also to be found on the
'Lea Canal' in both Hertfordshire and Essex. Pinniger, Syms and Ward (1950) referred
to the continued existence of a colony at Curtis Mill Green (presumably on the Roding).
D. A. Ashwell found a singleton of P. pennipes at Hatfield Forest in 1939. and it was
observed by D. A. Ashwell between 1940 and 1970 on the Chelmer/Blackwater
Navigation (B.R.C.). Extant specimens collected by Ashwell from these sites
(B.M.(N.H.) and C.E.M.) date from 30.5.1942 and 16.6.1957. There are several Suffolk
records from the Stour, the most recent of which is from Nayland, where it was recorded
by S. Beaufoy from 1940 to 1960. and, finally, there is a report of it in the grounds of
Thorpe Hall, Thorpe-le-Soken (E. H. N. Oakley. 1978, B.R.C.)
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