BRITISH BLOWFLIES (CALLIPHORIDAE) AND WOODLOUSE FLIES (RHINOPHORIDAE)

Draft key to British Calliphoridae and Rhinophoridae Steven Falk 2016
Calliphora – true bluebottles
In a British context, these are the familiar bluebottles that often enter buildings and
buzz about noisily. All of our species have metallic-blue tergites with a shifting dust
pattern and a non-metallic, grey-dusted thorax, sometimes with shifting stripes. The
upper surface of the lower calypters has long upright hairs which can cover most of
the surface in species like C. vicina, C. vomitoria and C. uralensis, but rather less in
the other three species. The face and antennae can be extensively reddish or orange.
The antennae are longer than other metallic species except Cynomya and the aristae
plumose. Non-metallic species occur abroad, notably in Australasia where some
species are partially orange, reddish or golden-furred (some are termed ‘golden
bottles’). The British species are relatively easily identified on external morphology
alone but male genitalia can be useful when dealing with wet samples. Very small
Calliphora individuals can be confused with Melinda species in the field but have
longer antennae, usually an extensively orange face and, in species such as C. vicina
and C. vomitoria, dark calypters.
All species lay eggs on carrion and several species are important in forensic
entomology. Different Calliphora species show subtly different preferences in the
carrion they use and this has been studied in northern Britain (Davies 1990, 1999).
Climate and temperature regimes also affect Calliphora assemblages, and diversity is
higher in the north, notably in areas like the Cairngorms and Pennines where 5 of the
6 British species can coexist. The only species unrecorded here, C. uralensis, is
strongly associated with northern seabird colonies. All Calliphora species seem to be
avid flower visitors and are also attracted to fresh excrement and Stinkhorn fungus.
The synanthropic species such as C. vicina and to a lesser extent C. vomitoria and C.
uralensis will also attempt to land on food and can be a nuisance and health hazard.
They can also breed in garbage and poorly stored food containing meat and dairy
products.
This is one of the largest blowfly genera (about 150 species) with an occurrence
centred on the Holarctic plus Australasian regions. C. genarum seems to be the only
further species found on the near continent and resembles C. stelviana but has shorter
aristal hairs, a dark face and a non-enlarged male postabdomen (see Marshall et. al.
2011, which is available online, for images). However, synanthropic North American
species such as C. livida (which resembles C. uralensis but has 3 postsutural intraalars)
could easily be bought over and would be easy to overlook. See Marshall et. al.
(loc. cit.) for a full account of the Calliphora species of Eastern Canada.
Key to species
1 Basicostae mostly pale brown, at least on apical half. Anterior thoracic spiracle
orange. Genal dilation pale brown on anterior two-thirds, dark grey on posterior
third, and entirely covered with black hairs. Male genitalia Fig 11.................vicina
- Basicostae blackish and anterior thoracic spiracle brownish or blackish. Genal
dilation usually entirely darkened (except some C. uralensis)............................…2
2 Calypters white or very pale grey, the upper calypter with a whitish or pale grey
rim. Build relatively slim, the abdomen clearly longer than wide in males, as long
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