Strumigenys argiola

From Fellner et al 2007: The distribution area of P. argiola is centred around the Mediterranean basin (Bernard, 1968), which implies that it is a thermophilic species mainly of open landscapes (see localities in southern Switzerland and Hungary). In Switzerland, for example, P. argiola was found in calcareous lean grassland (canton Jura) and in a dry pine forest (Pfynwald, canton Wallis). The new records from the extreme east and south of Austria fit rather well into the known distributional pattern: the nearest records approximately 200 km to the east of Lower Austria are from Central Hungary and the records from Carinthia parallel those from the southern Alps in Switzerland. As detailed above, the Austrian localities are also characterized by rather warm microclimatic conditions during the vegetation period.

Identification
A member of the argiola complex in the Strumigenys argiola group.

Distribution
This species is unusual for a Pyramica in its occurrence in southern Europe. It is currently known from Tunisia, Portugal, Spain, France, Switzerland, Germany, Italy, Corsica, Austria, Hungary, Serbia and Greece.

Distribution based on Regional Taxon Lists
Palaearctic Region: Austria, Azerbaijan, Balearic Islands, Croatia, France, Greece, Hungary, Iberian Peninsula, Israel, Italy, Portugal, Russian Federation, Spain, Switzerland, Tunisia.

Nomenclature

 *  argiola. Epitritus argiolus Emery, 1869a: 136, fig. 1 (q.) ITALY. Emery, 1875a: 75 (w.); Emery, 1875b: 473 (w.); André, 1883b: 404 (m.). Combination in Strumigenys: Baroni Urbani, 1998: 163; in Pyramica: Bolton, 1999: 1672; in Strumigenys: Baroni Urbani & De Andrade, 2007: 115. Senior synonym of barbara: Brown, 1949b: 44. See also: Kutter, 1977c: 168; Bolton, 2000: 288.
 * barbara. Epitritus argiolus var. barbara Santschi, 1923a: 136 (w.) TUNISIA. Junior synonym of argiola: Brown, 1949b: 44.

Worker
Bolton (2000) - TL 1.8-2.1, HL 0.46-0.50, HW 0.40-0.46, CI 89-93, ML 0.16-0.20, MI 35-40, SL 0.20-0.23, SI 50-52, PW 0.24-0.28, AL 0.50-0.55 (15 measured).

Among the sparse dacetine species of the West Palaearctic argiola is very distinctive because of its elongate narrow mandibles with spiniform apicodorsal tooth and orbicular cephalic pilosity, contrasting strongly with the other species, which are members of the baudueri- and membranifera-groups. Too much reliance should not be placed on the 4-segmented antennae of argiola as an identification character because this feature is duplicated in many West Palaearctic samples of species in the baudueri-group. Sub-Saharan Africa has seven species in the group (discussed under Strumigenys laticeps, below). S. argiola differs from all the Afrotropical species as follows.

1 No large subbasal lobe on the broad flattened scape.

2 Hairs on the leading edge of the scape curved or inclined toward the apex of the scape.

3 Four (very rarely 3) preapical denticles on each mandible.

4 No long strap-like or filiform hairs on the anterior clypea1 margin.

5 Postpetiolar spongiform lobes large.

6 Head relatively narrow (CI < 1 00).

7 First gastral tergite smooth or at most with weak superficial reticulation.

All the Afrotropical taxa have a large and strongly developed subbasal lobe on the scape, have hairs on the leading edge of the scape that are erect or directed toward the base of the scape, have 0-2 preapical denticles, have 4-6 long anteriorly directed strap-like or filiform hairs on the anterior clypeal margin, have postpetiolar spongiform lobes that are very small or absent, have relatively broad heads (CI at least 1 00), and have the first gastral tergite strongly reticulate-punctate.

The five species of the Strumigenys argiola group. that occur in the East Palaearctic and Oriental regions (Strumigenys hexamera, Strumigenys hirashimai, Strumigenys lachesis, Strumigenys sinensis, Strumigenys tisiphone) all have 6 antennal segments (although funicular segments 2 and 3 are very reduced in Strumigenys lachesis), as opposed to the 4 seen in argiola; also all have fewer than 4 preapical denticles on each mandible and have dense orbicular pilosity on the promesonotal dorsum.

S. argiola was redescribed in detail by Brown (1949a). Its circum-Mediterranean distribution is noted in Emery (1916), Brown (1949a) and Bernard (1967). More recently it has also been found in Spain (Espadaler, 1979), Switzerland (Kutter, 1977), Azerbaij an and Georgia (Arakelian & Dlussky, 1991), and Germany (Behr, Lippke & Colln, 1996); its presence in the Balkans was confirmed by Agosti & Collingwood (1987). It does not appear to penetrate the Afrotropical region (Bolton, 1983 and present study).

Type Material
Holotype queen (dealate), ITALY (Haliday) [examined].

Determination Clarifications
Bolton (2000) - A recent record of this species from Switzerland (Borcard, Borcard, et al., 1997) is a misidentified queen of baudueri (Baroni Urbani, 1998).