and it was assumed that local heavy rains which had swollen the Eastbrook Ditch, an
underground stream that surfaces in The Chase Nature Reserve and which drains excess
rain water into the River Rom, had caused the insect population living in the massed beds
of Yellow Flag Iris that blanket the banks of the stream, to emigrate into adjoining gardens.
It was noted that the very large Water ladybird colony, found previously on the banking,
had been dispersed by the surging floodwater, many yards into the Reed Sweet Grass,
which grows abundantly in the boggy soil close to the banks.
After the initial sighting at Eastbrookend during late May, no more spiders were found,
even though the adult season is from April to August, but in late July, while checking
reports of unusual ladybirds in the Dagenham Parish Churchyard, a white Misumena was
found there, in a flower of the Field Bindweed.
So, with the serene and placid atmosphere returned after the early Summer excitement of
the Misumena, do I inform my neighbours that, while helping with a wild flower survey
of the field containing the Eastbrook Ditch, not only were a variety of crickets and
grasshoppers noted, including Roesel's Bush-cricket, but the gaudy and fearsome Wasp
Spider, Argiope bruennichi, with its distinctive zig-zag web and the Wolf Spider, Pardosa
lugubris? I don't think so, as I am sure that news of yet another awesome spider in their
midst, would have them concreting over their gardens.
European green frogs in Essex
Jon Cranfield 14 Wiltshire Road, Eastleigh Hampshire S053 3EZ
mobs: 07769 644354-email jonathan.cranfield@btopenworld.com
This is a request for Essex Field Club Members to look out for 'noisy' green frogs around
Essex. There are three general species that people may find in Essex. The species include
the Pool Frog Rana lessonae, the Edible Frog Rana esculenta and the Marsh Frog Rana
ridibunda (see cover photographs).
The three species are very difficult to identify and distinguish in the field. I have been
working with Julia Wycherley, from the Surrey Amphibian and Reptile Group, who has
devised a way of identifying the different species from mating call analysis. From
recordings of these animals Julia can identify what species of European frog exist in any
population. Julia has been documenting the occurrence of the different introduced
European Frogs around the UK. This research may possibly reveal 'native' stock Pool
Frogs Rana lessonae that could be used to bring back the Norfolk Pool Frog, our seventh
native amphibian.
So far Essex European green frog populations have been identified in places such as
Hadleigh Castle Country Park (R. ridibunda), Lee Valley Regional Park (R. esculenta),
6
Essex Field Club Newsletter No. 39, November 2002