DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > SCHIZOPHORA > Calyptratae > Muscoidea > Scathophagidae (55 species)

(subfamilies: Delininae and Scathophaginae)

Although collectively, all of the members of this relatively small family are known as 'dung flies', only a few species of the Scathophaga genus actually breed in dung and, even though some of the other species may be found on dung at times, most of the family have varied and rather different life styles and larval habits.

Scathophagidae is one of a number of related families where identification from photos is difficult. Whilst a few of the more common species, such as Scathophaga stercoraria, can be readily identified, there will be situations when you're not actually sure you're dealing with a scathophagid as many of the defining features are shared with species of the much larger Muscidae/Fanniidae and, particularly, Anthomyiidae families.

Whilst the following abridged description applies, one of the most useful features that gives scathophagid flies quite a distinctive appearance, is that the back of the head is noticeably rounded with a patch of fine hair on the bottom part of the occiput. In general terms they are typically slender-bodied flies that range in size from as small as 3mm to around 12mm, usually with an elongated cylindrical abdomen that, in the males, is frequently enlarged at the tip; some species appear more robust due to a dense pubescence; body colour ranges from yellow to black, some being bicoloured; the head is normally higher than long, and the eyes are wide-set in both sexes; body and legs often with many bristles, sometimes densely covered with fine hairs; wings are usually clear, although in some species marked or darkened at the tip or along the cross-veins; the anal vein is long, typically reaching the wing margin.

The 55 British species are spread across 23 genera, which are separated into two subfamilies. All but four species are in the Scathopaginae, with the largest genera being Scathophaga with ten species and then Cordilura with nine. The most abundant and certainly the most frequently recorded species by a big margin is the common yellow dungfly, Scathophaga stercoraria, followed by Scathophaga furcata and Scathophaga suilla, thereafter the officially confirmed observations start dropping off quite significantly. Locally, apart from the first two, the situation is rather different, but given that there are only a handful of species with more than ten or so sightings the distribution list isn't that useful.

I have no idea how many of these species I'll be able to find and identify, but here's a little bit of information regarding those that I've photographed to date - mostly adaptations of Steven Falk's descriptions (from his Scathophagidae Flickr album), but also with due reference to Stewart Ball's illustrated key.

Cordilura ciliata - a larger than average scathophagid species with a shining black thorax and abdomen, and all-black legs. They have silvery-white dusting on the face and jowls and hind corner of the eyes, at the front of the thorax behind the head, on the front coxae, and on the sternopleuri above the mid coxae. The wings are distinctly yellow-tinted at the base.

The species particular favours wetland habitats where reeds and sedges are present, such as marshes, pond margins or along streams or canals, but can also occur in damp meadows and some woodland areas. It's been recorded a couple of times from South Hampshire (VC11), but never from Dorset (VC9) which is strange. 

Norellisoma spinimanum - a distinctive medium-sized species with a body that can vary from all-orange to dark brown and grey, but with legs that are always yellowish apart from dark markings on the mid and hind femora. The front legs are strongly-bristled.

It's a reasonably common and widespread species across southern and central areas, occurring in various habitats such as rank grassland and open areas of woodland where there are docks, particularly Broad-leaved Dock where the larvae develop in the leaf petioles. The adults are predatory with two generations during the year, such that they may be seen from May right through to October.

Ceratinostoma ostiorum - a relatively large, robustly-built, coastal species with an overall grey to slightly brownish- grey appearance, heavily dusted in part and with distinct brownish markings on top of the thorax. It is easily separable from the other two species that you are most likely to find in similar coastal or saltmarsh habitat, namely Scathophaga calida and Scathophaga litorea, by the entirely grey, rather than orange or partially orange, tibiae found in those species. The frons, although not visible in the photo featured below, is rather dark brownish-black, palps yellow-brown and rather long, and the front tibiae have several long anteroventral bristles. Females have a broader, flatter abdomen than the males.

Although this species has been recorded from various coastal locations around the country it seems to be rather localised. At the time of writing only six have been officially recorded from either Dorset (VC9) or South Hampshire (VC11). Adults may be seen from spring to autumn and are most likely to be found resting on wet mud or shingle along the shore, around estuaries or in saltmarsh. The larvae develop in wet rotting seaweed.

The Scathophaga species are featured and described on the following page ....

Updated Nov.24 (v.3)