The Essex Naturalist
15
landscaped before the interesting pioneer vegetation can develop or they are
scrubbing over. A case in point is Great Totham pits. In 1983 there were spreads
of Cladonia portentosa and the shiny brown Coelocaulon aculeatum, as well as
nine other terricolous species. In 1995, the C. portentosa had gone, shaded out,
while C. aculeatum and the other species were rare and depauperate. Ironically,
the willows that have shaded out this rich flora themselves bear a good
corticolous (bark) flora, including Parmelia perlata. Nevertheless, the trend is
worrying and I have no new records of Coelocaulon in Essex since 1987.
Lastly, mention should be made of the British Lichen Society Churchyard
Survey, which has been running since 1993, the aim being to record the lichens
from at least one churchyard in each 10km square in lowland Britain. A number
of inconspicuous species are being found at various churchyards in the county, a
few examples being Acarospora umbilicata, Lecania turicensis, Lecanora conferta
and Sarcopyrenia gibba. A BLS visit to St Nicholas' church, Castle Hedingham,
in September 1995, recorded 69 lichens and the same total was also recorded
from St Giles', Great Maplestead, later the same day, an indication of the
importance of churchyards for lichens in Essex.
References
Hawksworth, D L and McManus, P M, 1992. Lichens: changes in the lichen flora on trees in
Epping Forest through periods of increasing then ameliorating sulphur dioxide pollution.
Essex Naturalist 11:92-101.
Skinner, ] F, 1983. The Lichen Flora of the Roman River Valley Conservation Zone, Essex.
Nature in North East Essex. 1983: 17-36.
Neuropteroidea in Essex
Colin W Plant
14 West Road, Bishopi Stortford, Hertfordshire CM23 3QP
The Rothamsted Insect Survey light trap at the Writtle Agricultural college has
continued to provide a steady stream of lacewings throughout the year. This site
is noted for the very small coniopterygid Lacewing Semidalis pseudouncinata
Meinander which was discovered new to Britain from both this trap and a
similar one at Wisley Gardens in Surrey during 1990 (Plant 1992). The whitish
insect is only a few millimetres across the wings and closely resembles the
whitefly pests of indoor plants. It has been steadily expanding its European range
northwards in recent years and is evidently partly assisted by the popularity of
ornamental conifers in gardens; the larvae are associated with aphids and/or
scale insects on members of the Cupressaceae, especially Thuja and
Chamaecyparis species. It is likely to be present in many of the larger gardens
across Essex and should be looked for by gently sweeping likely trees with a
black net in May, June and especially August. I would be pleased to receive
specimens for identification.