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

Distribution One old British record from Clovelly, Devon
(3 August 1927, H. Womersley) and two single more recent
ones from Shelf Held Coppice, Wyre Forest, Worcestershire
(7 August 1988, P.J. Chandler) and from Chafer Wood,
Yorkshire (7 August 2000, R. Crossley).
Habitat The Clovelly specimen was found on a wooded
slope with several small sedgy streams. That from Shelf
Held Coppice was in a recently coppiced area by the stream,
where fungus gnats were very numerous on that occasion
(80 species being recorded).
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.
Status A very poorly known, but distinctive species,
obviously very restricted in Britain. At Clovelly it was
coincidentally found together with the first British specimen
of Macrocera longibrachiata Landrock. The Clovelly site
was revisited by P.J. Chandler in July 1986 but no evidence
was found of its continued survival there and the habitat
described by Edwards (1927) does not appear to exist there
now; the entire woodland area there has evidently been
heavily managed, with only sparse ground vegetation and
very little dead wood retained. The Wyre Forest site has
also been revisited (1993) when it was found that the
coppiced Alders (Alnus) had not regrown and the area had
consequently become a grassy clearing with an
impoverished fauna. 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 Ditching of streams with a loss of streamside
vegetation and marshy areas. Clearance of adjacent trees
which provide damp shaded conditions.
Management and conservation Maintain wooded streams
in a natural state free from excessive disturbance, so
favouring a rich marginal vegetation and trees for shade. In
areas which are to be coppiced, this should be done on
rotation and the vicinity of streams and other wet areas
should be excluded, as this usually results in drying out and
development of rank herbaceous vegetation. Retain any
dead wood and old or diseased trees, which may provide
breeding sites.
Published sources Chandler (1990); Coldwell (2001);
Edwards (1927); Hutson, Ackland & Kidd (1980).
MACROCERA INVERSA
A fungus gnat
Order DIPTERA
Macrocera inversa Loew, 1869
DATA DEFICIENT
Family KEROPLATIDAE
Identification Keyed by Hutson, Ackland & Kidd (1980)
under the name M. bipunctata Edwards.
Distribution Only two sites in north-west England are
known: Tilberthwaite Ghyll, Lancashire (21 July 1923,
F.W. Edwards); Bowness, Westmorland (18 June 1889,
G.H. Verrall).
Habitat Moorland in upland areas.
Ecology Biology unknown. The larvae possibly develop as
predators beneath turf.
Status An undoubtedly very restricted species in Britain,
but possibly overlooked. Status revised from RDB 2 (Shirt
1987 and Falk 1991). This is the Macrocera bipunctata
Edwards, 1925 of Kloet & Hincks (1976) and was listed
under that name by Shirt (1987). 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 The drainage of upland bogs and afforestation
could have serious effects.
Management and conservation Maintain sites in a natural
state, free from excessive disturbance, ensuring a high
stable water level in boggy areas which may provide
breeding sites. Traditional moorland management to create
vegetation mosaics could be beneficial.
Published sources Chandler (1990); Edwards (1925).
MACROCERA LONGIBRACHIATA
A fungus gnat
DATA DEFICIENT
Order DIPTERA
Family KEROPLATIDAE
Macrocera longibrachiata Landrock, 1917
Identification Keyed by Hutson, Ackland & Kidd (1980).
Distribution A single old British record from Clovelly,
Devon (3 August 1927, H. Womersley) and one recent
record from Weston Big Wood, Somerset (1 September
2001, D. Gibbs).
Habitat The original specimen was found on a wooded
slope with several small sedgy streams. The recent record
from near Bristol was from a calcareous woodland. P.J.
Chandler found the species by a heavily shaded stream in a
limestone gorge in Belgium in 1990.
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.
Status A very poorly known species, obviously very
restricted in Britain. At Clovelly it was coincidentally found
together with the first recorded British example of
Macrocera fastuosa Loew. A recent revisit to this site in
July 1986 by P.J. Chandler did not result in the rediscovery
of either species and the precise habitat described by
Edwards (1927) does not appear to exist there now. The
woodland there has been heavily managed with only sparse
ground vegetation and very little dead wood retained. 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 Ditching of streams with a loss of streamside
vegetation and marshy areas; clearance of adjacent trees
which provide damp shaded conditions.
Management and conservation Maintain wooded streams
in a natural state, free from excessive disturbance,
encouraging a rich marginal vegetation and trees for shade.
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