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

Ecology There is a Russian record of association with the
fungus Gyromitra esculenta. The larvae may develop in
other soft fungi in the Scottish sites. Adults recorded in
June.
Status Only two males have been found in Britain, one of
them recently but it may have been overlooked elsewhere
within this range. In Europe it is a boreo-alpine species
known from northern Scandinavia and the Alps, but also
extends across Siberia to Alaska and Canada. Not listed in
Shirt (1987) or Falk (1991).
Threats Clearance of native forests for intensive forestry or
agriculture. Overgrazing by deer preventing natural
regeneration. Removal of old trees or dead wood, which
may support host fungi.
Management and conservation Maintain forest cover,
retaining any old trees and dead wood and ensure
succession of such habitats by restricting grazing and other
damaging activities.
Published sources Chandler (1992b).
PSEUDEXECHIA PARALLELA
A fungus gnat LOWER RISK (Nationally Scarce)
Order DIPTERA
Family MYCETOPHILIDAE
Pseudexechia parallela (Edwards, 1925)
Identification Keyed by Edwards (1925) and Chandler
(1978d). The male genitalia were figured by Stackelberg
(1948).
Distribution This was known as British only from the
female holotype found at Newmarket, Suffolk (23
September 1888, G.H. Verrall) until it was found to be
frequent in wetland sites surveyed by the NCC from 1987 to
1989 in East Anglia (Suffolk, Norfolk, Cambridgeshire) and
Wales (Glamorgan, Pembrokeshire, Merionethshire,
Caernarvonshire, Denbighshire, Anglesey). It was also
found in Ireland in 1983 (Chandler et al. 2000).
Habitat Marshes and fens, wet heaths and bogs.
Ecology Biology unknown. Other species of the genus
develop in soft gill fungi, including both terrestrial and
lignicolous species. Adults recorded from June to October.
Status This was unrecorded in Britain for almost a century
after its original discovery but there are now records for
three sites in Suffolk, 21 sites in Norfolk, Chippenham Fen
NNR in Cambridgeshire and fourteen sites in Wales. Status
revised from RDB 1 (Shirt 1987) and from Extinct (Falk
1991).
Threats Drainage of wetlands. Overgrazing or nonrotational
cutting on some sites.
Management and conservation Maintain stable water
level and existing vegetation structure and mosaic of
habitats. Grazing should be at a low level and where
appropriate grazing or cutting should be carried out on
rotation. Removal of the litter layer on which host fungi
may develop should be avoided.
Published sources Chandler et al. (2000); Edwards (1925).
PSEUDORYMOSIA FOVEA
A fungus gnat LOWER RISK (Nationally Scarce)
Order DIPTERA
Family MYCETOPHILIDAE
Pseudorymosia fovea (Dziedzicki, 1910)
Identification The male genitalia were figured by
Dziedzicki (1910).
Distribution A northern and western species: Forest of
Dean, Gloucestershire; several sites in Yorkshire; Helvellyn
Gill, Cumberland; Glamorgan, Denbighshire, Flintshire;
several sites in Perthshire; the Mar Lodge Estate in
Aberdeenshire; the Spey Valley in Elgin and Easterness;
other sites in Easterness, East Ross and East Sutherland.
Habitat Damp woodland, mostly broad-leaved but mixed at
some Scottish sites.
Ecology This has been reared in Germany from a terrestrial
agaric, Tricholoma flavobrunneum. Adults recorded in June
to July, September and October.
Status A distinctive species but poorly known before 1980
as of 30 recorded sites, 27 are more recent. It seems
particularly widespread in the Scottish Highlands and
Chandler (1987a) also recorded it from Ireland. Status
revised from RDB 1 (Shirt 1987) and from RDB 3 (Falk
1991).
Threats Clearance of native woodland for intensive forestry
or agriculture. Removal of old trees or damage to soil
structure which could affect survival of mycorrhizal fungi.
Management and conservation Maintain woodlands in a
natural state, with all successional stages, ensuring its
continuity in the future. Avoid damage to litter layer or soil
structure to safeguard terrestrial fungi.
Published sources Chandler (1987a); Edwards (1923,
1925); Kidd & Ackland (1970).
RYMOSIA ACTA
A fungus gnat
Order DIPTERA
Rymosia acta Dziedzicki, 1910
DATA DEFICIENT
Family MYCETOPHILIDAE
Identification Chandler (1994b) keyed this species and
figured the male genitalia, which had also been figured by
Laštovka & Matile (1974).
Distribution Only known as British from single males
found at six sites in Scotland: Kilvrecht (1987) and Allt nan
Bogair (2000), Rannoch, Perthshire; Luibeg, Mar Lodge
Estate, Aberdeenshire (2000); Dulsie, Elgin (1999);
Craigellachie NNR, Easterness (2002); Migdale Wood, East
Sutherland (1995).
Habitat The known localities are broad-leaved or mixed
woodland.
Ecology Biology unknown. The larvae probably develop in
soft fungi. Adults recorded in June and August to October.
Status A recent discovery in Britain which is widespread in
northern Europe and may prove more widespread in
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