Parydra (Parydra) aquila (Fallén, 1813)

(Figs. 1, 26–29)

Ephydra aquila Fallén 1813: 247; locus typicus not given [“ Sverige “]; lectotype ♀, des. by Clausen & Cook (1971) [NHRS, Clausen & Cook 1971].

Parydra bituberculata Loew 1862: 165–166; type-locality: „Middle States“; lectotype ♂, des. by Cresson (1949) [MCZ, Cresson 1949]; synonymy by Clausen & Cook (1971).

Parydra nitida Cresson 1915: 70; type-locality: „Potlatch, Idaho “; holotype ♂ [ANSP, Cresson 1915]; synonymy by Clausen & Cook (1971).

Parydra tibialis Cresson 1916: 150–151; type-locality: „Oak Creek Canyon, Arizona, 6000 ft. alt.“; holotype ♂ [KSUC, Cresson 1916]; synonymy by Clausen & Cook (1971).

Parydra papulata Cresson 1949: 247; type-locality: „Friday Harbor, Washington “; holotype ♂ [ANSP, Cresson 1949]; synonymy by Clausen & Cook (1971).

Additional material examined: 455 specimens from Finland, Germany, Greece, Italy, Portugal and European Russia including new country records for Croatia and Georgia: CROATIA: 1♀, 24.vi.2017, fishponds 1.5 km ne Stražanac [45.635°N 17.097°E]; 1♀, 25.vi.2017, fishponds 2 km s Oriovac [45.147°N 17.747°E]; 4♂♂ 3♀♀, 24.vi.2017, fishponds Ripnjaci [45.521°N 16.936°E]; 6♂♂ 1♀, 27.vi.2017, floodplain Danube 0.6 km s Podunavlje [45.625°N 18.813°E]; 1♂, 27.vi.2017, floodplain Danube 1 km se Tikveš [45.668°N 18.853°E]; 1♂ 1♀, 27.vi.2017, floodplain Danube 1.5 km ne Kopačevo [45.612°N 18.800°E]; 3♂♂ 1♀, 26.vi.2017, floodplain Drava 3 km n Petrijevci [45.638°N 18.542°E]; 3♀♀, 26.vi.2017, floodplain Drava n Bistrinci [45.699°N 18.393°E]; 2♂♂ 3♀♀, 26.vi.2017, floodplain Drava ne Nard [45.664°N 18.486°E]; 1♀, 25.vi.2017, floodplain Sava 3 km ne Zbjeg [45.090°N 17.931°E]; 1♀, 4.vii.2018, Krka n Lozovac [43.802°N 15.966°E]; 1♀, 22.vi.2017, Piljenice [45.435°N 16.856°E]; 1♂, 19.vii.2018, Šarena Jezero near Knin [44.027°N 16.223°E]; 4♂♂ 1♀, 26.vi.2017, small river 5.2 km sse Lacići [45.590°N 18.235°E]; GEORGIA: 1♂, 30.vi.2019, 1.4 km wsw Ilmazlo [41.424°N 45.008°E]; 2♀♀, 13.vii.2019, Algeti river n Partskhisi [41.579°N 44.567°E]; 1♀, 13.vii.2019, Chrami river n Tikilisa [41.597°N 43.960°E]; 1♂ 1♀, 30.vi.2019, Debeda river n Khanji-Gazlo [41.357°N 45.005°E]; 1♂, 30.vi.2019, Debeda river n Kirach-Mughanlo [41.340°N 45.051°E]; 5♂♂ 1♀, 30.vi.2019, Debeda river w Didi Mughanlo [41.389°N 44.943°E]; 2♂♂, 1.vii.2019, Iori river 8.5 km se Sagaredscho [41.668°N 45.388°E]; 1♂, 2.vii.2019, Jandara reservoir 2.8 km se Mzianeti [41.451°N 45.212°E]; 2♂♂, 11.vii.2019, Kirkhbulaki river e Qulalisi [41.327°N 43.484°E]; 1♂ 2♀♀, 8.vii.2019, Kura river 1.5 km w Khtsisi [41.980°N 43.655°E]; 1♀, 30.vi.2019, Kura river 1.6 km e Ilmazo [41.428°N 45.043°E]; 1♂, 29.vi.2019, Kura river 2 km s Karajalari [41.599°N 44.960°E]; 3♂♂, 30.vi.2019, Kura river 2.0 km ese Ilmazo [41.420°N 45.044°E]; 1♀, 9.vii.2019, Kura river 2.3 km nne Teliani [41.948°N 44.282°E]; 1♀, 8.vii.2019, Kura river n Akhalsheni [42.005°N 43.723°E]; 3♂♂ 2♀♀, 8.vii.2019, Kura river nw Akhalsopeli [42.013°N 43.765°E]; 2♂♂ 2♀♀, 29.vi.2019, Kura river, Rustawi [41.551°N 45.010°E]; 2♂♂, 29.vi.2019, Kura valley 2.7 km w Akhalsheni [41.484°N 45.034°E]; 1♂, 11.vii.2019, lake Kartsakhi wsw Kartsakhi [41.236°N 43.249°E]; 2♀♀, 10.vii.2019, lake Nadarbazevis [41.999°N 44.287°E]; 1♀, 2.vii.2019, Mariini Canal 3.4 km n Jandari [41.473°N 45.167°E]; 1♂, 12.vii.2019, Saghamo lake se banks [41.297°N 43.754°E]; 1♀, 10.vii.2019, small lake 2.2 km ene Imera [41.650°N 44.215°E]; 1♂, 8.vii.2019, Soramula river 1.7 km ene Agara [42.047°N 43.841°E].

Diagnosis: A large species with short and inconspicuous setae and setulae and hardly any wing colouration (Fig. 1). The small wart like protuberances at the base of medial scutellar seta, hind tibia with silver-white dusting apically and basally, distinct contrast between subshining dorsal and densely dusted ventral face, high and broad phallus in lateral view (Fig. 28), postgonite broad based and S-shaped in dorsal view (Fig. 26) are each unique within European Parydra.

Distribution in Europe: A common species distributed widely across Europe. Its absence from some of the larger islands including Iceland, the Canary Islands, Mallorca and Sardinia might be due to their lack of suitable habitats. Parydra aquila has been recorded from northern Finland up to 66°N (GBIF 2024) which may represent the northern limit of its distribution within Europe. Outside Europe P. aquila occurs in Morocco (Vitte 1991), in Asia north to Japan (Krivosheina 1995, Miyagi 1977 as bituberculata) and is widely distributed in America north of 30°N (Clausen & Cook 1971).

Biology: An aquatic to semiaquatic species reaching its highest populational density in detritus rich inland habitats. Adults are found from March to October and the species is polyvoltine at least in central and south Europe. Stigmatomyces parydrae Thaxter, 1917 has been reported to grow on P. aquila (Santamaría & Rossi 1998). The larva and puparium are described by Krivosheina (1987). Larvae live within detritus or among organic material. Their exact diet is unknown.