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

Ecology The larvae are aquatic filter feeders at the meniscus
of water bodies, especially against emergent structures such
as semiaquatic plants. Adults recorded from March to
October.
Status Fifteen known post 1960 sites, boosted by the
records from two sites on the Galashiels Dipterists’ field
meeting in 1988. Status revised from RDB 3 (Shirt 1987).
Threats The destruction of wetlands through drainage and
mismanagement of water levels with a loss of breeding
sites; pollution such as agricultural runoff and
eutrophication. Ditching and canalization of streams and
rivers is detrimental.
Management and conservation Maintain a high, relatively
stable, water level and emergent marginal vegetation. Use
rotational management of ditches and ponds where
necessary.
Published sources Disney (1975, 1999); Goldie-Smith
(1990); Nelson (1982).
introduced species as previously supposed. On the continent
it is widespread but especially favours the Mediterranean
region. Currently there is inadequate information to assess
the risk of extinction. This species is not listed in Shirt
(1987) and was assigned to RDB K in Falk (1991).
Threats The drainage and reclamation of fens for
agriculture, or the lowering of water levels through local
abstraction or mismanagement, resulting in a loss of
standing water. Pollution such as agricultural runoff could
also render sites unsuitable and may be a significant threat
to any surviving Norfolk Broads colonies.
Management and conservation Maintain a high water
level at sites and good water quality. Prevent the
encroachment of carr or scrub onto open fen. Where
necessary continue any established cutting regimes,
although ensuring that these are carried out on rotation.
Published sources Ashe et al. (1991); Edwards (1932,
1939); Hart (1954); Morgan (1987); Rees & Rees (1989);
Rees & Snow (1990); Snow et al. (1998).
ANOPHELES ALGERIENSIS
A mosquito
Order DIPTERA
DATA DEFICIENT
Family CULICIDAE
CULISETA LONGIAREOLATA
A mosquito
Order DIPTERA
DATA DEFICIENT
Family CULICIDAE
Anopheles algeriensis Theobald, 1903
Identification Keyed by Snow (1990).
Distribution Until recent years only known from the
following Norfolk sites: Catfield Fen NNR (1932), Foulden
Common (1932, 1953), Waxham (1932, 1953), Hickling
Broad NNR (1932) and Three Hammer Common, near
Neatishead (1953). In 1987 it was discovered at Cors Goch
in Anglesey and was then closely studied at that site (Rees
& Rees 1989).
Habitat All known sites are fens. There is a requirement for
standing water.
Ecology Larvae develop in standing water amongst fen
vegetation, often including shallow puddles at the margins
of fens. There is probably only one generation per year,
although adults have been recorded from May to September.
The larvae within a single population seem to develop at
different rates so as to produce adults over a period of time.
This may facilitate survival in unfavourable conditions.
Overwintering seems to occur exclusively in the larval
stage. Females are said to bite man voraciously.
Status An apparently rare and restricted species, although
abundant at the Norfolk sites in 1932; the more recently
discovered Welsh site suggests that it may be underrecorded
in this part of Britain. However, it was not
recorded elsewhere during the NCC Welsh Peatland
Invertebrate Survey from 1987 to 1990 and it is not known
whether it was present in samples from the similar survey of
East Anglian wetlands which included its former Norfolk
sites. A search at Foulden Common in 1989 failed to locate
the species (Snow et al. 1999). Cors Goch is a reserve of the
North Wales Wildlife Trust and a SSSI as is Foulden
Common; Hickling Broad is a NNR. Ashe et al. (1991)
recorded it as new to Ireland from around emergent
vegetation in sheltered bays of a deep lake in Co. Clare
(Lough Bunny) (1989), tending to confirm that it survives
as relict populations in the British Isles, rather than being an
Culiseta longiareolata (Macquart, 1838)
Identification Keyed by Snow (1990).
Distribution Only recorded from Brownsea Island, Dorset
(pre 1969); the Portsmouth area of Hampshire (1940);
Epsom, Surrey (1953); Broadbottom, Cheshire (1985).
Details of the Cheshire record are not available and this was
omitted from the map in Snow et al. (1998).
Habitat The larvae were found in a foul, brackish pool at
Portsmouth and the Brownsea Island record may also refer
to brackish conditions. The inland record from Epsom refers
to larvae in a water butt. In the Mediterranean region, where
the species is widespread, the aquatic stages have been
recorded from a very wide range of conditions, including
freshwater, brackish or even heavily polluted with organic
matter. Larvae have been found in tanks and containers both
inside and outside buildings and larval sites vary from direct
sunlight to heavy shade.
Ecology Larvae aquatic in the above locations. Adult
females bite man seldom, if at all, a factor which could lead
to some under recording.
Status A very poorly known species of uncertain British
status and it may not be a true native. Abroad it is recorded
from the Canary Islands and Azores, throughout the
Mediterranean region and extends across to India, but in
continental Europe it has not been reported north of Paris.
Currently there is inadequate information to assess the risk
of extinction. Status revised from RDB 1 (Shirt 1987) and
from RDB K (Falk 1991).
Threats Unclear as it is clearly tolerant of some degree of
pollution and is capable of utilising a wide range of
situations. Climatic factors are probably the major
controlling factor in Britain and it is possible that none of its
recorded populations are permanent.
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