Part 2: Nematocera and Aschiza not dealt with by Falk (1991) - JNCC

Scotland. Currently there is inadequate information to
assess the risk of extinction. Not listed in Shirt (1987).
Threats Clearance of native woodland for intensive forestry
or agriculture.
Management and conservation Maintain woodlands in a
natural state with a mosaic of habitats. Avoid drainage or
disturbance to soil structure which could affect survival of
host fungi.
Published sources Chandler (1994b).
RYMOSIA AFFINIS
A fungus gnat
Order DIPTERA
Rymosia affinis Winnertz, 1863
VULNERABLE
Family MYCETOPHILIDAE
Identification Keyed by Chandler (1994b). The male
genitalia were figured by Dziedzicki (1909) under the name
Rymosia gracilipes Dziedzicki.
Distribution Scattered records in southern England and
Wales: Devon, Hampshire, Hertfordshire, Suffolk,
Cambridgeshire, Herefordshire; Breconshire, Flintshire.
Habitat Damp broad-leaved woodland.
Ecology This species has been reared in Britain from the
stipes of terrestrial gill fungi of the genera Russula and
Amanita. There are foreign records from other genera of
terrestrial agarics including Hygrocybe, Hygrophoropsis,
Tricholoma, Rhodophilus, Lepista, Macrolepiota, Entoloma
and Cortinarius. It is common in the Mediterranean region
where it aestivates in caves, and the Flintshire site was from
a cave (Plas Heaton, 20 April 1951, J. Hobart). Adults
recorded virtually throughout the year including the winter
months, suggesting that it normally hibernates as an adult in
this country.
Status Recorded widely in the early part of the last century
but the only post 1960 records are Yarner Wood NNR and
Bridford Wood, both Devon (October 1980) which suggests
that the species has undergone a decline. It has, however,
been found recently in the Isle of Man and in the Burren
Grikes in County Clare, Ireland (Chandler et al. 2000).
Threats Clearance of woodland for agriculture or intensive
forestry.
Management and conservation Maintain woodlands in a
natural state, retaining any old trees and avoid damage to
litter layer or soil structure which could adversely affect
mycorrhizal and other terrestrial fungi.
Published sources Chandler et al. (2000); Edwards (1913,
1925).
RYMOSIA ARMATA
A fungus gnat LOWER RISK (Nationally Scarce)
Order DIPTERA
Family MYCETOPHILIDAE
Rymosia armata Lackschewitz, 1937
Identification Keyed by Chandler (1994b); the male
genitalia were figured by Chandler (1977b, ventral view and
gonostylus; 1994b, tergite 9 and aedeagus) and the
ovipositor by Chandler (1994b).
Distribution Now known to be locally frequent in East
Anglia (Norfolk) with the following additional sites
recorded in England: Powler’s Piece, Devon (1988);
Shortheath Common, Hampshire (1990); Burton Mill Pond,
Sussex (1989); Whixall Moss, Shropshire (1936); Agden
Bog, Yorkshire (1990). In Wales it is widespread with
records from Glamorgan, Breconshire, Radnorshire,
Carmarthenshire, Cardiganshire, Montgomeryshire,
Denbighshire and Anglesey but only two sites are known in
Scotland: Pitmaduthy Moss, East Ross (1976) and
Killimster, Caithness (1990).
Habitat Most sites are bog or fen including open and more
or less wooded areas: amongst Carex rostrata, C.
paniculata, Juncus flushes and acidic basin mires; the two
southern English sites (Hampshire, Sussex) are wooded
pond margins.
Ecology Biology unknown. The larvae probably develop in
soft fungi. Adults recorded in March and May to December.
Status Only recognised as British in 1977 and only one pre
1970 site is known, but it has now been found in 27 sites in
26 hectads. Status revised from RDB 2 (Shirt 1987) and
RDB 3 (Falk 1991).
Threats Drainage of wetlands for agriculture or forestry
and extraction of peat; overgrazing or non-rotational cutting
of fen vegetation.
Management and conservation Maintain stable water
levels and existing vegetation structure of wetlands. Avoid
non-rotational cutting or removal of litter layer on which
fungus hosts may be dependent.
Published sources Chandler (1977b, 1994b).
RYMOSIA BRITTENI
A fungus gnat LOWER RISK (Nationally Scarce)
Order DIPTERA
Family MYCETOPHILIDAE
Rymosia britteni Edwards, 1925
Identification Keyed and the ovipositor figured by
Chandler (1994b); the male genitalia were figured by
Edwards (1925).
Distribution Known from scattered records before it was
found to be locally frequent during the NCC wetland
surveys of the Oxford district (Berkshire, Oxfordshire) and
East Anglia (Norfolk, Cambridgeshire); older records were
from Oxford (Museum window), Oxfordshire (1915); Cwm
Coedcerrig, Monmouthshire (1977); Bridge of Brown, Elgin
(1982); Fort William, Westerness (1921).
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