DIPTERA > BRACHYCERA | Higher Diptera

MUSCOMORPHA > SCHIZOPHORA > Acalyptratae > Ephydroidea > Ephydridae (153 species)

(subfamilies: Discomyzinae, Ephydrinae, Gymnomyzinae, Hydrellinae and Ilytheinae)

Of the 150 or so recognised shorefly species, there are actually relatively few that have a distinct coastal or saltmarsh habitat preference. In fact, there only seem to be 15 or 16 species that are specifically found in this type of location that are listed as either 'common' or 'local'. There are a handful of 'scarce' or 'rare' species, but those are mostly restricted to other areas. And, of course, I'm not sure how many of these species listed as 'local' can actually be found in my area.

As far as I can tell, the most likely species that I could encounter are Ephydra and Paracoenia fumosa as featured below, Haloscatella dichaeta and Hydrellia cochleariae. Then, it would possibly be some of those designated as 'local' such as Atissa pygmaea, Parydra pubera, Philotelma nigripenne, Psilopa compta, leucostoma and nana, Scatella ciliata and Scatella subgutta. However, when sifting through all the currently available records on the NBN Atlas I could only find a couple that have been confirmed from either Dorset (VC9) or South Hampshire (VC11).

Without doubt, these ephydrid coastal and saltmarsh species are one of the most poorly recorded groups of flies that I've come across. Normally, I would have passed them by because of the difficulty with identification, but I'm indebted to Tony Irwin on the Diptera UK FB group - who is one of the country's leading authorities on these species - for giving me help and guidance.

There are two Ephydra species, Ephydra macellaria and Ephydra riparia. The females are inseparable and the males can only be distinguished with microscopic examination. As such, they are usually left as Ephydra sp. They are closely related to Paracoenia fumosa with both species having facial hair and a hairy mouth margin, and five pairs of dorsocentral bristles (one pre- and four post sutural). Apart from their general appearance with the latter typically being darker with a shiner thorax, Ephydra has three divergent pairs of fronto-orbitals whereas Paracoenia fumosa only has two. The leg colour is also different, but that can sometimes be difficult to see in certain light. But, the other difference, if visible, is that the Ephydra species have feet with long straight claws with greatly reduced pulvilli. Paracoenia fumosa have shorter, curved claws and normal pulvilli (white pads) that can usually be seen even if the fly is standing on water.

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