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

Broad NNR (1988) and Whitwell Common (1989), Norfolk;
Badger’s Wood, Cambridgeshire (1998); Brampton (1965),
Alconbury (1966) and Warboys (1984), Huntingdonshire;
West Town (1928), Gloucestershire; Abbot’s Moss,
Cheshire (1941); Blacktoft Sands, Yorkshire (1976); Cors
Caron NNR (1987) and Cors Fochno (1988, 1989),
Cardiganshire; Llanbrinmair Moor (1988) and Ddrum ddu
(1989), Montgomeryshire.
Habitat Unclear; although the Welsh sites include areas of
bog or fen, some other localities are dry woodland or
woodland edge; even garden habitats are suggested and
some individuals have been found at light indoors.
Ecology Biology unknown. Larvae of this genus have been
reared from a range of situations including clumps of turf,
rotting wood or cave walls and are considered to be
predaceous. Adults recorded from June to November.
Status There are only 19 British records, but all but three
are post 1960 and thirteen are post 1970. Earlier records
include two from light traps and another indoors, suggesting
that this may be a mainly nocturnal species which could be
overlooked for this reason. More recent records are mainly
from water or pitfall trapping on wetland sites. Status
revised from RDB 3 (Shirt 1987). This species was
temporarily referred to as Macrocera nana Macquart
(Chandler 1990) but this name has now been found not to
apply to this species. The wide extent of occurrence
indicates Nationally Scarce.
Threats Uncertain other than drainage of wetlands and
clearance of any dead wood and old or diseased trees which
may support breeding sites.
Management and conservation Maintain a high stable
water level and retain any dead wood and old trees, also
ensuring the continuity of these into the future.
Published sources Chandler (1990); Edwards (1941);
Gibbs (2002); Hutson, Ackland & Kidd (1980); Hutson &
Kidd (1974).
MACROCERA ZETTERSTEDTI
A fungus gnat LOWER RISK (Near Threatened)
Order DIPTERA
Family KEROPLATIDAE
Macrocera zetterstedti Lundström, 1914
Identification Keyed by Hutson, Ackland & Kidd (1980).
The separation from M. estonica Landrock requires some
comment, because the latter may have vein R 4
weak or
absent on one or both wings and the humeral area may be
either more or less distinctly yellow or darkened in both
species. The male genitalia provide the best confirmation.
Distribution Five sites in the central Highlands of Scotland:
Stuchd an Lochain and Ben Chalun, Perthshire (1932, F.W.
Edwards); Upper Quoich, Mar Lodge Estate, Aberdeenshire
(2000, A. Godfrey); Aviemore, Elgin (1937, F.W.
Edwards); Cairngorm NNR, Easterness (1984, J.H. Cole).
Habitat The three montane sites are above the tree line. The
Aviemore record may actually apply to nearby areas of the
Cairngorms, as the exact location was not recorded. Upper
Quoich is a Caledonian Pine forest remnant with open areas
nearby.
Ecology Biology unknown. Larvae of this genus have been
reared from a range of situations including clumps of turf,
rotting wood and cave walls and are considered to be
predaceous. Adults recorded in May and June.
Status A poorly known montane species with only two post
1960 records but possibly under-recorded in view of its
infrequently sampled habitat. The Welsh record cited by
Chandler (1990) was in error, based on a specimen of
Macrocera estonica lacking vein R 4
. Status revised from
RDB 1 (Shirt 1987 and Falk 1991). The lack of biological
information on the habitat requirements of the species,
leading to uncertainty concerning the threats to its survival,
indicates Data Deficient.
Threats Drainage and afforestation. Above the tree line,
skiing can lead to problems such as soil erosion and loss of
vegetation. In common with other montane species, M.
zetterstedti may be threatened by climate change.
Management and conservation Maintain sites in a natural
state free from excessive disturbance.
Published sources Chandler (1990); Edwards (1933).
MACRORRHYNCHA ROSTRATA
A fungus gnat
VULNERABLE
Order DIPTERA
Family KEROPLATIDAE
Macrorrhyncha rostrata (Zetterstedt, 1851)
Identification This was described and the head and male
genitalia figured by Chandler (1992b).
Distribution Only known from Hampshire: Brinken Wood
(5 June 1988), Mark Ash Wood (10 June 1988), woods by
Beaulieu River (13 July 1990), all New Forest (P.J.
Chandler) and The Knowles (13 July 1995) and Denny
Wood (18 June 2000), New Forest (I. Perry); Whitmoor
Vale (12 July 1990, P.J. Chandler and A.E. Stubbs).
Habitat Broad-leaved woodland with old trees and dead
wood. The New Forest sites are relatively dry although in
the vicinity of streams, while Whitmoor Vale is a wet slope
with many springs.
Ecology Biology unknown. Larvae of this group spin webs
on various substrates and are either carnivorous or feed on
fungal spores. A female was found around a standing dead
Beech (Fagus) trunk at Mark Ash Wood so dead wood may
be the favoured larval habitat. Adults of most
Macrorrhyncha, including the other (common) British
species M. flava Winnertz, feed at flowers especially of
umbels, for which their elongate proboscis is adapted. It is
not known whether M. rostrata, which has a shorter
proboscis than M. flava, has this habit too. Adults recorded
in June and July.
Status A recent addition to the British list but fairly large
and distinct, suggesting that it has a genuinely restricted
distribution. It has recently been found in Jersey, Channel
Islands and may only occur near the south coast in Britain.
Not listed in Shirt (1987) or Falk (1991).
Threats Clearance of native woodland for commercial
forestry or agriculture; removal of over mature or dead trees
which may provide the larval habitat.
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