Sarcophagidae

Fleshflies

DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > SCHIZOPHORA > Calyptratae > Oestroidea > Sarcophagidae (63 species)

(subfamilies: Miltogramminae, Paramacronychiinae and Sarcophaginae)

As noted above, the Sarcophagidae is split into three very distinct subfamilies. Miltogramminae with 18 species that are cleptoparasites of solitary wasps and bees, sometimes called 'satellite flies' as a few species have the habit of following potential hosts back to their nests. Paramacronychiinae with just 6 species of flies that have diverse biologies ranging from the predation of snails to parasites or parasitoids of other insects or mammals. And, Sarcophaginae, the largest subfamily with 41 species, with all but four being in the widespread Sarcophaga genus. The biology of these species is again very varied ranging from predation of insects to breeding in carcasses, animal faeces or decomposing organic matter.

The Sarcophaga genus includes the typical black and grey fleshflies with a stiped thorax and tessellated or chequered abdomen, noticeably large feet and bright red eyes. They like warm weather when they'll frequently be seen basking on sunlit surfaces fences, posts, rocks or other structures. They are common around refuse dumps, but can also be found in various habits including calcareous grasslands, forest edges, gardens and around sand dunes.

General family characteristics are given as small to large (3-22mm) although usually over 7mm, generally stout and bristly flies; the thorax usually has three dark stripes on top, and the abdomen is striped, spotted, banded or checked with the markings shifting tones depending on the angle of light; most species are grey to blackish grey, although some are yellow-grey, green-grey or almost entirely black lustrous, never metallic blue or green; the face is concave and lacks a central ridge; the antennal arista is bare to plumose; wings usually hyaline, sometimes infuscated anteriorly, or variously ornamented with dark markings; vein M1 always curving forward, sometimes ending in vein R4+5 at the wing margin or before, making cell r4+5 petiolate; lower calypter usually broadly rounded-triangular, in a very few cases smaller and more or less round to elliptical; subscutellum narrow and flat, not swollen; hyperpleural (meral) bristles always present; the posterior spiracles are covered by an anterior and posterior lappet, usually the anterior lappet a narrow fringe and the posterior one forming an operculum.

The first species featured below has a rather distinctive conically-produced frons, which makes it easy to identify as a Metopia sp. The males of three of the five species have the anterior part of the frons glistening silvery-white. They can be separated by some fine features that unfortunately can't be determined from these photos but, in view of the habitat and the fact that Metopia argyrocephela is by far the more common species, it has to be the most likely option.

Coincidently, at the same sandy heathland location, albeit over three consecutive years, I also found both of the Miltogramma species. lurking around the burrows of ground-nesting bees. These two species are very similar, although Mitogramma punctata is the larger and more robust with a well-dusted body, whereas Miltogramma germani is notably slimmer with a much shinier appearance. That said, other distinguishing features are important, so I was pleased that they were both positively identified by experts on the FB UK Diptera group.

Similarly, with identification of Nyctia halterata although, once seen, this species is easily the most recognisable sarcophagid by virtue of its shining black body coupled with wings that are darkened along the front edge.

Of the remaining species, there are very few that could be reliably identified from photos, and certainly none of the Sarcophaga species as they all require microscopic examination. Even with good quality, well-detailed photos and expert help, the best assessment would be a member of the Sarcophaga sp. (carnaria group), which covers three virtually identical species, Sarcophaga carnaria, subvicina and variegata. The most useful comment I've had with these is to look for a "broad parafacial in combination with a pair of stout medio-marginals on the third tergite". If those features cannot be determined with confidence, then it's best to accept that they cannot be identified. Now and again, I'll post a photo to either the general UK Diptera group or the Sarcophagidae Recording Scheme page if it looks a bit different or distinctive in any way, but in the most part I now label all these as Sarcophaga sp. That said, one of the individuals I photographed was tentatively identified as Sarcophaga haemorrhoa. It's one of the more common species although, interestingly, it's never been officially recorded from Dorset.