Essex Dragonflies (Odonata): An update
in England during the late 1990s. In 1996 it had been recorded from the River Wey in Surrey, had
Started to colonise the River Nene in Northamptonshire and more recently had been noted from the
River Stour in Suffolk. Ian Johnson had seen two males of the species in July 1997 near Nayland, and
Cham had recorded two males along the Stour near Bures in July 1998. Further exploration by Cham
along the Stour in 1999 revealed a sizeable population between Bures and Nayland, with evidence of
breeding. Also in 1999, adults of L. fulva were reported from the River Colne at Earls Colne, suggesting
the possibility of colonisation of this river from the Stour. Informed by these discoveries, the first
author searched the lower reaches of the River Colne in June 2000. On the 12th June two or three
specimens of L. fulva were observed on the Colne adjacent to a meadow on the outskirts of Colchester
(TL9826). A clear view was observed of a female 'basking' on a branch over-hanging the river, and one
or more partially teneral males were seen in flight at the same spot: a sheltered bend in the river, with a
belt of trees on the northern bank. There were no opportunities to re-visit the site in good weather
during the rest of the flight period in 2000. and the site was inaccessible in 2001 due to foot-and mouth
restrictions. However, the colony on the Stour is reported to be 'going from strength to strength', with
high numbers being seen at the end of June and early July (Cham 2001).
As well as this re-colonisation of Essex by the Scarce Chaser, Essex had the distinction of being the first
county for records of the new British colonist - the Small Red-eyed Damselfly Erythromma viridulum.
Dewick & Gerussi (2000) reported the first British sightings of this species on 1711' July 1999. Egg-
laying and definitive identification of the species at the same pond followed on 23rd July, and subsequently
the species was observed on two more ponds, at one of which it was the dominant species. The latest
record for 1999 was 21st September. Parr (2000) reported the discovery of new sites in the Isle of Wight
during the 2000 season, together with several new localities in Essex, including one inland site in the
Lee Valley, with a total of 20 known localities by the end of that year. The 2001 season saw a concentration
of field-work effort in Essex, and the discovery of still more sites scattered across the county, but
particularly well represented in the east. So far these are all still-water sites, usually ponds with abundant
floating vegetation such as water-lilies and Potamogeton spp. Although it is possible that this species
had been present well before its discovery by Dewick & Gerussi, and simply confused with E. najas,
this seems unlikely. The two species certainly are very similar to the casual observer, but the flight
period of E. viridulum lasts longer into late summer than that of E. najas. In addition, E. viridulum has
turned up since 1999 at regularly and closely observed sites where neither it nor E. najas had been seen
before. The map (Fig. 1) gives all known sites in Essex for E. viridulum, based on information received
up to 2002. Further information on E. viridulum, and how to distinguish it from E. najas is given in
Cham (2000b). The 2001 season also saw the discovery of new sites in other counties of south and cast
England -Norfolk, Suffolk. Kent and Hampshire (Cham 2001).
Though it is too early to report detailed findings from the current survey, it has been established that
all the more localised of the species present in the mid 1980s are still to be found in the county.
Calopteryx virgo is still present at its single known breeding site on the Roman River, south of
Colchester. Lestes dryas has been found in at least two new sites, one in the north-east of the county,
the other on Canvey Island. It was also re-found at Wat Tyler Counuy Park, from where it had been
feared lost. Platycnemis pennipes continues to confirm the more optimistic picture of its status in
Essex as reported in Benton (1997/8), with strong colonies on the River Stour, the Roman River and
elsewhere. The same is true of our other 'recovery7 species, Brachytron pratense which now appears
to be well established along the east coast and Thames Estuary, with a scattering of inland sites such
as the Lee Valley, the Chelmer/Blackwater and Markshall, near Coggeshall. Cordulia aenea continues
to breed on the Epping Forest ponds, though 'wanderers' have been seen further afield. There are
few recent records of the migratory Sympetrum species since the 'invasion' year of 1995. Provisional
maps for the remaining more common and widespread species indicate no dramatic changes.
Essex Naturalist (New Series) 19 (2002)
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