Gerris (Gerris) argentatus Schummel, 1832

Gerris argentatus Schummel: Nieser & Moubayed (1986: 248), “ Liban […] Ammik”

Gerris (Gerris) argentatus Schummel: Fent et al. (2011: 43), “ Lebanon ”; Aukema et al. (2013: 41) and Ghahari et al. (2023j: 8), “ Lebanon ”, quotations of Nieser & Moubayed (1986).

Material examined. Survey material: Basin of Litani: Ammiq, 6.V.2004, 1 ♀ micr., 1 ♀ macr., CFC; Litani below Ain Zarka spring, 11.XI.2005, 1 ♀ macr., MLUB; Basin of Oustouane: Oustouane at bridge Cheikh Zennad, 9.V.1999, 1 V instar nymph (♂), MLUB.

Extra-survey material: Beka´a (Coll. Am. Un. Beirut), 8.IX.1952, K. Christiansen leg., L. Hoberlandt det. 1971, 1 ♂, 2 ♀♀ macr., 2 V instar nymphs (NMPC).

General distribution. The range of this species is attributable to a Centrasiatic-Europeo-Mediterranean distribution with extension also to some countries of Northern Europe, Northern Territory of Russia and central part of Siberia (see Kanyukova 2006, Damgaard et al. 2014).

Remarks. The only published record for Lebanon came from a mountain area, i.e. “Ammik” [= Ammiq, also transliterated as Aammiq or Aamiq]—confirmed also on the basis of this new specimen sampled at hilly-mountain altitude. However, although in Middle East other data exist from high altitudes, for example that from “ Kermanshah ”, Iran (see Samin et al. 2011), even at more southern latitudes, the species may occur at lower altitudes, e.g. in lowland at “Hadera”, Israel (Linnavuori 1960). Furthermore, it was collected at hilly altitude in Iraq (Jaczewki 1964) or from lowland to high altitude in Maghreb: Morocco and Algeria (Poisson & Gauthier 1926, Gheit 1995). Therefore, it was expected that this species would be occurring at lower altitudes also in Lebanon, as proved by the record of the Oustouane River.

This species was considered until recently as a Sibero-European or a Palaearctic species (e.g. Fent et al. 2011, Cianferoni & Mazza 2012, Berchi et al. 2018), but since it occurrence in Maghreb (see Poisson & Gauthier 1926, Gheit 1995, Damgaard et al. 2014) and Central Asia (see Kanyukova 2006, Damgaard et al. 2014) and its apparent absence in the Far East (see Kanyukova 2006) and Oriental Asia (existing records from this area are results of misidentification: Damgaard et al. 2014) is to be attributed to Centrasiatic-Europeo-Mediterranean extending a little more to the north (see Vigna Taglianti et al. 1999).