Notes on Shore Flies (Diptera: Ephydridae) from Finland and north-western Russia

Abstract The recent checklist of the Ephydridae of Finland by Zatwarnicki and Kahanpää (2014) mentioned 13 ephydrid species as new for Finland without further details. This paper presents detailed records for those species and a few other species of interest. Four species are recorded for the first time from Russia. Trimerina indistincta Krivosheina, 2004 is herein considered as a new junior synonym of Trimerina microchaeta Hendel, 1932, syn. nov.


Introduction
Finland is an exceptional country in having a record of regularly published checklists of the order Diptera, including shore flies. Three of such lists have been published during the last century: Frey (1941), Hackman (1980) and Kahanpää and Salmela (2014). The Diptera fauna of the country is well studied in comparison to most other countries, but far from perfectly understood.
The most recent list of the Finnish shore fly fauna is  in Kahanpää and Salmela (2014). The Finnish Ephydridae have attracted relatively little attention: few Finnish dipterologists have studied them and no coordinated study of the fauna has been made. The Finnish Museum of Natural History in Helsinki (MZH) holds by far the largest ephydrid collection in the country. Existing faunal works are essentially based on museum material collected between the years 1900 and 1960, mostly by sweepnetting. After a long hiatus, interest in acalyptrate flies resurged in the 21st century among Finnish amateur entomologists. The newer ephydrid material generally remains in private collections. Zatwarnicki (1997) included a list of the species known from the country by the mid-1990s. Twelve species have been added to the fauna after 1997. Chronologically first is Notiphila pollinosa Krivosheina by Krivosheina (1998), then Calocoenia paurosoma (Sturtevant & Wheeler) and Parydra arctica Clausen by Krivosheina (2000), Coenia curvicauda (Meigen) by Haarto and Winqvist (2002), Gymnoclasiopa pulchella (Meigen) by Winqvist (2002), Notiphila major Stenhammar by Kahanpää and Winqvist (2003), Trimerina microchaeta Hendel (as T. indistincta Krivosheina) by Krivosheina (2004), Philotelma defectum (Haliday) by Mathis et al. (2009), Atissa pygmaea (Haliday) by Winqvist (2011), and Hecamedoides unispinosus (Collin), Parydra mitis (Cresson) and P. nigritarsis Strobl by Kahanpää (2013). The identity of the North European Glenanthe species was resolved by Zatwarnicki and Mathis (2012).
Thirteen additional species of Ephydridae were recorded for the first time from Finland in the recent checklist . The checklist format did not allow for the inclusion of record data. This paper provides the previously unpublished records on which the checklist was based. Additionally, one new synonymy is proposed: Trimerina indistincta Krivosheina, 2004 is treated as a junior synonym of Trimerina microchaeta Hendel, 1932 (syn. nov.). After inclusion of all additions and corrections to the fauna, the number of shore fly species recorded from Finland is now 112.
Some material from north-western Russia, adjacent to the Russian-Finnish border, was also examined during the preparation of the Finnish checklist. Four species are recorded from Russia for the first time.

Materials and methods
All the specimens discussed in this paper are deposited at the Zoological Museum of the Finnish Museum of Natural History in Helsinki (MZH) unless otherwise specified. Most MZH specimens have unique specimen identifiers in the form of a URL (Uniform Resource Locator). The URL can be used as a web address: it points to a web page with details of the sample in question. While we cannot guarantee that the web content is available in the future, the address (URL) will remain unique. Standard abbreviations are used for the Finnish biogeographical provinces; see the Fauna Entomologica Scandinavica book series or Heikinheimo and Raatikainen (1971) and Heikinheimo and Raatikainen (1981) for details and maps.
Finnish insect collectors usually use a national uniform grid system (yhtenäiskoordinaati sto, YKJ) for mapping and labeling purposes. The Darwin Core (DC) field "verbatimCoordinates" is used for the YKJ coordinates printed on labels. The DC fields "decimalLatitude" and "decimalLongitude" in the Taxon treatments section are given in World Geodetic System 1984 (WGS84) decimal degrees. Where no collector-supplied coordinates were available, the records were georeferenced by the senior author on the basis of the collecting locality.
The identity of all included species is based on the study of primary types conducted by the junior author, except for Hydrellia tarsata Haliday and Scatophila mesogramma (Loew), for which interpretations are based on Collin (1966) and Sturtevant and Wheeler (1953) respectively.
The order of species follows .

Distribution
Widespread in Europe; also occurs in the Russian Far East (Kamchatka) .

Taxon discussion
After examination of primary types of Trimerina microchaeta Hendel and T. indistincta Krivosheina we suggest to synonymize these two species. Krivosheina (2004) provided three characters to separate T. indistincta from T. microchaeta: a gena-to-eye ratio of 0.17 (versus 0.20 for T. microchaeta), yellow mid and hind coxae (versus all coxae partially dark), mid and hind tibiae entirely yellow (versus mid and hind tibiae with a dark band). These characters separating the two species are not consistent and fall within the variation range of T. microchaeta. Both nominal taxa have essentially the same male terminalia with characteristic postgonostyli (=postsurstyli) bearing short and apically rounded antero-ventral processes as illustrated for T. indistincta by Krivosheina (2004).

Notes
The holotype of Trimerina indistincta is shown in Fig. 1a.

Diagnosis
Best identified by structures of the male genitalia as figured by Collin (1966) and Canzoneri and Meneghini (1983).

Distribution
First recorded from Finland by . Widespread in Europe; also known from North Africa and Pakistan (Zatwarnicki 1988.

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966).

Distribution
First recorded from Finland by . Central and Western Europe . The Finnish records are the first from Northern Europe.

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966).

Distribution
First recorded from Finland by . Widespread in Europe, it is recorded also from the Russian Far East .

Ecology
No reliable records of the host plant of this species could be found.

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966) and Canzoneri and Meneghini (1983) under the name Hydrellia flaviceps (auct. nec Meigen).

Distribution
First recorded from Finland by . Widespread in Europe and probably across the Palaearctic Region, but poorly known

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966).

Distribution
First recorded from Finland by . Northern, Western and Central Europe .

Ecology
Larvae have recently been found feeding on Alisma (Robbins 1990) and Stratiotes, possibly also Lemna and Alisma (see Deonier 1971).

Notes
Correctly identified by Richard Frey and Lauri Tiensuu but the record was never published. Specimen http://id.luomus.fi/GV.16611 is illustrated in Fig. 1b.

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966) and Canzoneri and Meneghini (1983).

Distribution
First recorded from Finland by . Widely distributed in Europe and North Africa .

Ecology
Larval host plant(s) unknown.

Diagnosis
Best identified by structures of the male genitalia as illustrated by Collin (1966).

Distribution
First recorded from Finland by . Western and Central Europe, also recorded from Bulgaria .

Biology
The Finnish specimen was caught on water soldiers (Stratiotes), which is a host plant of H. tarsata (Przhiboro 2004).

Notes
Three most likely conspecific females were caught together with the male.

Distribution
First recorded from Finland by . A West-Palaearctic species found in almost all European countries and also in North Africa .

Taxon discussion
Hecamedoides unispinosus is much more common in Finland than H. glaucellus. The Fennica collection of MZH has only three specimens of the latter species: http:// id.luomus.fi/GV.19146 from Turku (see Fig. 2b) and two specimens from Terijoki (=Russia, Leningrad Oblast, Zelenogorsk).

Distribution
Previously recorded from Norway, Germany and Slovakia . New for Russia.

Distribution
New for Russia. North Holarctic, known in Europe from Norway, Sweden and Finland . First noted from Finland by Krivosheina (2000) from Kilpisjärvi. The new records presented here expand the known European distribution of the species both south-and eastwards.

Distribution
First recorded from Finland by . Previously known from Archangelsk Oblast (NW European Russia) and Kazakhstan (Krivosheina 2001).

Diagnosis
Scatophila iowana Wheeler has entirely black legs, a yellow haltere, a matt brown mesonotum and a brownish microtomentose abdomen. It lacks the pair of pronounced facial setae typical for S. despecta (Haliday). The wing and mesonotal patterns of Scatophila iowana resemble those of S. caviceps (Stenhammar). Males of these two species can be identified by the shape of the central part of the face: somewhat protruding between well-defined antennal grooves in S. iowana, weakly concave and without antennal grooves in S. caviceps.
The anepisternum of S. iowana is rather uniformly brownish; S. caviceps has a grey anepisternum with two brown spots, one around the base of the anepisternal bristle and one at the ventral margin.
The male terminalia of S. iowana are characterized by the anterior margin of the epandrium, which is slightly concave, and the aedeagus, which consists of three sclerites. In S. caviceps the anterior margin of the epandrium bears a medial projection and the aedeagus is a one-piece structure.

Distribution
First recorded from Finland by . Scatophila iowana is a Holarctic species. It is probably widespread in Europe, but its distribution remains poorly known .