Gerris (Gerris) costae (Herrich-Schäffer, 1850)

Gerris (Gerris) costae costae Bacchi & Rizzotti Vlach 2005: CD-ROM; 2007: CD-ROM. Gerris (Gerris) costae Terzani et al. 2012: 269 .

RECORDS. Tuscany: Camaldoli, 900 m, Poppi (AR), (TCRI) (Bacchi & Rizzotti Vlach 2005; 2007); Case Boschetti, spring pond, 710 m, Gaviserri, Stia (AR), 20.V.2009, FT & SR leg., 1 M (TCFI); Gorga Nera lake, 1300 m, San Godenzo (FI), 26.V.2008, FC & GM leg., 1 M, 1 F macr (CCFI); Falterona Mount, 13.VI.1965, BL leg., 2 M, 1 F macr (MZUF); Idoli lake, 1370 m, Monte Falterona, Stia (AR), 20.V.2009 SR leg., 1 M (CCFI); Podere Pratalino lake, 965 m, Bibbiena (AR), 15.VI.2007, FT leg., 1 M, 1 F macr (TCFI); idem, 25.IV.2008, GM & FT leg., 1 F macr (CCFI); Vignano ponds, 600 m, Poppi (AR), 25.VI.2006, FC & GM leg., 1 M, 1 F macr (CCFI).

Remarks. This is a Turano-European species (with extension to British Isles). In Italy, G. costae is more common in the mountains (recorded up to about 2,700 m a.s.l.). Here, we consider the species sensu Cianferoni (2011) without subspecies.