Aphaenogaster peloponnesiaca

The species prefers slightly drier habitats than Aphaenogaster ovaticeps and tends to avoid sunny places. It is a diurnal species; foraging workers were observed mostly in stream valleys inside plane and oak forests, on stones and rocks inside deciduous forests, recreation areas close to streams, occasionally inside buildings or in maquis with oak shrubs. There are only two observations from rocky parts of coniferous, cypress copse. The one observed nest was monogynous, under a stone in a dry, artificially planted pine forest near a chapel, with fewer than 50 workers.

Identification
Aphaenogaster peloponnesiaca, together with Aphaenogaster ovaticeps, are the only species with regularly oval head similarly converging anterad and posterad. Both species are very similar and differ mostly in body coloration. Aphaenogaster ovaticeps has head and mesosoma yellowish-brown, brown to dark brown while in A. peloponnesiaca has body yellow to rusty-yellow. In other morphological characters both species are very similar. However, A. peloponnesiaca has slightly higher elevated anterior part of mesonotum, head behind eyes more distinctly converging posterad, distinctly convex propodeal dorsum, and longer and thinner propodeal spines. Longitudinal and oblique sculpture of head in A. peloponnesiaca is slightly further expanded than in A. ovaticeps, and often covers anterior 2/3 of the head while in A. ovaticeps the sculpture covers usually only anterior half of the head. Both species differ in distribution patterns, A. ovaticeps is known from Italy (Apulia, Friuli-Venezia Giulia, Liguria), Slovenia, Croatia, Bosnia and Hercegovina, Serbia, Montenegro, Albania, and northern Greece south to the western Sterea Ellas (Epirus, Ionian Islands, western Sterea Ellas, southern Macedonia) while A. peloponnesiaca is known from southern and western Sterea Ellas and Peloponnese of southern Greece. We have no confirmed records of sympatry in Sterea Ellas or Peloponesse, where the species could co-occur. Both species were collected around Ambracian Gulf, but they differ in habitat preferences, with A. peloponnesiaca perferring less humid areas than A. ovaticeps. Additionally, there is no cline in the morphological differences between the species. The species pair is probably an example of vicariant taxa.

Among other species of the A. splendida group the most similar to A. peloponnesiaca is Aphaenogaster splendida, due to slim body and elongate and slim antennae and legs, but it differs in more pale-yellow head and mesosoma, anterior part of mesonotum situated distinctly higher over the surface of pronotum, and less regularly oval more distinctly sculptured head. Yellow species of the Aphaenogaster festae complex differ in stouter body, legs with distinctly swollen hind femora, and strongly developed head sculpture covering almost entirely its frontal part, except occipital area. Slim and yellow species of the Aphaenogaster kervillei complex distinctly differ in more elongate head, sides of head behind eyes more or less strongly converging posterad and longitudinal sculpture of head covering only anterior one-third to half of head.

Distribution based on type material
Greece.

Nomenclature

 * . Aphaenogaster peloponnesiaca Salata et al., 2021: 319, figs. 8, 12, 33, 35, 53-56, 88 (w.q.) GREECE.

Type Material

 * Holotype worker: GREECE, Peloponnese | Arkadia, n. Kapsas |37°37.634 N / 22°19.735 E |3 IX 2013, 766 m |L. Borowiec ||Collection L. Borowiec | Formicidae | LBC-GR01309 (CASENT0887506, MNHW-DBET).
 * Paratypes: 1 gyne, 27 workers: the same data as holotype (CASENT 0887507–CASENT0887534, MNHW-DBET, MHNG, CASC).
 * Paratypes: 5 workers: GREECE, Pel. Messinia | Karveli, 600 m |37.07591 N / 22.20633 E |17 VI 2016, L. Borowiec ||Collection L. Borowiec | Formicidae | LBC-GR02108 (CASENT0887535–CASENT 0887539, MNHW-DBET).