Gerris (Gerris) argentatus Schummel, 1832

Berchi, Gavril Marius, Cianferoni, Fabio, Csabai, Zoltán, Damgaard, Jakob, Olosutean, Horea, Ilie, Daniela Minodora, Boda, Pál & Kment, Petr, 2018, Water striders (Heteroptera: Gerromorpha: Gerridae) of Romania with an update on the distribution of Gerris gibbifer and G. maculatus in southeastern Europe, Zootaxa 4433 (3), pp. 491-519 : 499-500

Gerris (Gerris) argentatus Schummel, 1832

Material examined. ROMANIA: Alba County: Cioara de Sus [pond], 46°22ʹ23ʺN 23°19ʹ54ʺE, 1040 m a.s.l., 08.vii.2014, leg. & det. P. Boda, 1 ♂ (mi) ( PBDH) . Bihor County: Bolcaș [stream], 47°21ʹ24ʺN 22°13ʹ50ʺE, 125 m a.s.l., 05.v.2012, 1 ♂ (ma) 1 ♀ (ma) . Botoșani county: Dragalina [stream], 48°02ʹ36ʺN 26°27ʹ04ʺE, 149 m a.s.l., 03.viii.2012, 1 ♂ (ma) 3 ♀♀ (ma) . Buzău County: Movila Banului [stream], 44°58ʹ06ʺN 26°39ʹ47ʺE, 74 m a.s.l., 21.vii.2014, 1 ♀ (ma) . Călărași County: Ciocănești [stream], 44°11ʹ37ʺN 27°00ʹ44ʺE, 12 m a.s.l., 20.vii.2014, 1 ♀ (ma); Oltenița [pond], 44°05ʹ37ʺN 26°38ʹ10ʺE, 23 m a.s.l., 20.vii.2014, 1 ♀ (mi) . Caraș-Severin County: Bocșa [pond], 45°21ʹ24ʺN 21°43ʹ28ʺE, 190 m a.s.l., 23.iv.2017, 1 ♂ (ma); idem [pond near stream], 45°21ʹ34ʺN 21°45ʹ10ʺE, 231 m a.s.l., 23.iv.2017, 1 ♀ (ma); Mehadica [pond], 45°02ʹ12ʺN 22°16ʹ18ʺE, 298 m a.s.l., 29.viii.2012, 1 ♂ (ma) . Cluj County: Șutu [stream], 46°37ʹ40ʺN 23°33ʹ10ʺE, 521 m a.s.l., 08.vii.2014 , leg. & det. P. Boda, 1 ♀ (ma) (PBDH); Țaga [stream], 46°56ʹ31ʺN 24°03ʹ26ʺE, 266 m a.s.l., 08.viii.2011, 1 ♂ (ma). Constanța County: Crucea [stream], 44°31ʹ12ʺN 28°14ʹ00ʺE, 49 m a.s.l., 07.viii.2015, 1 ♂ (mi) . Dolj County: Vârtop [stream], 44°12ʹ28ʺN 23°18ʹ58ʺE, 141 m a.s.l., 27.vii.2012, 1 ♂ (ma) . Galați County: Oancea [stream], 45°55ʹ15ʺN 28°06ʹ37ʺE, 12 m a.s.l., 01.viii.2012, 1 ♂ (ma) 1 ♀ (ma) . Giurgiu County: Pietrele [stream], 44°03ʹ14ʺN 26°07ʹ40ʺE, 21 m a.s.l., 20.vii.2014, 1 ♀ (ma); Schitu [stream], 44°09ʹ32ʺN 25°50ʹ09ʺE, 61 m a.s.l., 20.vii.2014, 1 ♂ (mi) . Olt County: Fălcoiu [stream], 44°13ʹ58ʺN 24°20ʹ22ʺE, 95 m a.s.l., 28.vii.2012, 1 ♂ (ma); Siliștioara [stream], 43°46ʹ17ʺN 24°32ʹ27ʺE, 36 m a.s.l., 28.vii.2012, 1 ♂ (mi) 1 ♂ (ma) . Prahova County: Străoști [stream], 45°01ʹ51ʺN 26°13ʹ31ʺE, 136 m a.s.l., 30.vii.2012, 1 ♂ (ma) . Sălaj County: Plopiș [pond], 47°06ʹ57ʺN 22°37ʹ47ʺE, 320 m a.s.l., 24.vi.2013, 1 ♂ (mi) 4 ♀♀ (mi) . Sibiu County: Alma [pond], 46°13ʹ17ʺN 24°29ʹ25ʺE, 370 m a.s.l., 06.viii.2011, 2 ♂♂ (ma) ; Sibiu [lake], 45°45ʹ45ʺN 24°07ʹ31ʺE, 445 m a.s.l., 10.x.2014 , leg. & det. H. Olosutean, 1 ♂ (mi) 1 ♀ (ma) (HOSR); idem [pond], 45°47ʹ16ʺN 24°07ʹ36ʺE, 409 m a.s.l., 18.vii.2014, leg. & det. H. Olosutean, 4 ♂♂ (ma) 4 ♀♀ (ma) (HOSR). Suceava County: Chiril [pond], 47°24ʹ33ʺN 25°32ʹ23ʺE, 758 m a.s.l., 04.v.2017, 1 ♂ (ma); Dolhasca [pond], 47°25ʹ51ʺN 26°37ʹ13ʺE, 217 m a.s.l., 30.vii.2011, 1 ♀ (ma) . Timiș County: Becicherecu Mic [stream], 45°50ʹ01ʺN 21°02ʹ19ʺE, 86 m a.s.l., 08.viii.2015, 1 ♀ (ma); Dumbrăvița [pond], 45°48ʹ22ʺN 21°15ʹ50ʺE, 96 m a.s.l., 19.xii.2014 , leg. I.A. Rădac, det. G.M. Berchi, 2 ♂♂ (ma) ( GBCR); Ghiroda [stream], 45°45ʹ42ʺN 21°19ʹ51ʺE, 95 m a.s.l., 12.xii.2014 , leg. I.A. Rădac, det. G.M. Berchi, 2 ♀♀ (ma) ( GBCR); Timișoara [stream], 45°45ʹ17ʺN 21°16ʹ36ʺE, 101 m a.s.l., 23.iv.2013, 2 ♀♀ (ma); Lugoj [pond], 45°40ʹ44ʺN 21°55ʹ56ʺE, 116 m a.s.l., 08.viii.2015, 1 ♀ (ma); Satchinez [pond], 45°57ʹ32ʺN 21°02ʹ01ʺE, 89 m a.s.l., 07.ii.2013 , leg. I.A. Rădac, det. G.M. Berchi, 1 ♀ (ma) ( GBCR); Victor Vlad Delamarina [stream], 45°38ʹ16ʺN 21°54ʹ06ʺE, 134 m a.s.l., 22.iv.2017, 1 ♂ (ma) . Tulcea County: Câșlița [stream], 45°19ʹ58ʺN 29°14ʹ15ʺE, 1 m a.s.l., 05.viii.2015, 2 ♂♂ (mi) 1 ♀ (mi); Pardina [stream], 45°18ʹ41ʺN 29°03ʹ29ʺE, 1 m a.s.l., 05.viii.2015, 1 ♂ (mi) 2 ♀♀ (ma); Rahman [stream], 44°47ʹ50ʺN 28°16ʹ24ʺE, 86 m a.s.l., 06.viii.2015, 1 ♂ (ma); Smârdan [pond], 45°15ʹ39ʺN 28°03ʹ43ʺE, 13 m a.s.l., 21.vii.2014, 1 ♀ (mi); Sulina [channel], 45°07ʹ46ʺN 29°35ʹ40ʺE, 1 m a.s.l., 11.viii.2013 , leg. & det. H. Olosutean, 31 ♂♂ (ma) 22 ♀♀ (ma) (HOSR); idem [channel], 45°07ʹ39ʺN 29°35ʹ40ʺE, 1 m a.s.l., 10.viii.2013, leg. & det. H. Olosutean, 48 ♂♂ (ma) 41 ♀♀ (ma) ( HOSR); Vadu [channel], 44°32ʹ56ʺN 28°53ʹ02ʺE, 1 m a.s.l., 06.ix.2016 , leg. & det. H. Olosutean, 8 ♂♂ (ma) 7 ♀♀ (ma) ( HOSR); Vulturu [stream], 45°10ʹ14ʺN 29°00ʹ05ʺE, 1 m a.s.l., 05.viii.2015, 1 ♂ (ma) 1 ♀ (mi) . Vâlcea County: Valea lui Stan [pond], 45°20ʹ47ʺN 24°12ʹ17ʺE, 337 m a.s.l., 08.viii.2015, 1 ♀ (mi).

Published records. Horváth (1878, 1897, 1898a, b), Montandon (1907), Motaș et al. (1962), Benedek (1970), Bucșa (1970), Kis (1972, 1975, 1976), Schneider (1973), Kis & Davidescu (1994), Kecskés (1997), Ilie (2001, 2003, 2006, 2007, 2014), Ilie & Davideanu (2002), Davideanu et al. (2004), Ilie & Vițchii (2007), Olosutean & Ilie (2008a, 2010a, c, 2013a), Skolka (2008), Ilie & Olosutean (2009, 2012), Olosutean et al. (2009, 2013), Ilie & Ban- Calefariu (2010), Berchi et al. (2011).

Remarks. In Romania, this species was identified at 41 sites at an elevational range of 1–758 m a.s.l. ( Fig. 1 ). It was found from February to December in streams, channels, lakes and ponds. The micropterous/macropterous ratio was: 0.08: 0.92 (total 18/204).

In Finland, G. argentatus is known to be partially bivoltine, dimorphic in summer, and only macropterous in winter ( Vepsäläinen 1974b).

Distribution. Palaearctic: Euro-Siberian (cf. Andersen 1995, Damgaard et al. 2014). For the Romanian distribution, see Fig. 5 .

Figures

FIGURE 1. Boxplots representing the elevational distribution of Gerridae in Romania. Circles represent outliers and asterisks represent extreme values.

FIGURES 2–7. Distribution in Romania: (2) Limnoporus rufoscutellatus (Latreille, 1807); (3) Aquarius najas (De Geer, 1773); (4) Aquarius paludum paludum (Fabricius, 1794); (5) Gerris argentatus Schummel, 1832; (6) Gerris costae fieberi Stichel, 1938; (7) Gerris lacustris (Linnaeus, 1758). Blank dots represent published records, question marks represent dubious published records of A. najas and solid dots represent records from this study.