Metanotal groove absent or shallow; propodeal dorsum relatively flat, propodeal declivity deeply concave, posterior protrusions absent or weakly to well developed; body densely punctate, appears dull (only C. nitidescens and C. schulzi have sculpture partially reduced on the lateral sides of mesosoma); the whole body bearing short to long, thick, pale and erect setae, and additional short appressed microsetae; head, mesosoma, and gaster uniformly blackish-brown to black (only C. aktaci has gaster yellowish-brown); polymorphic species.

All known species have similar biological preferences and were most often collected in warm and arid habitats within coniferous forests, especially pine forests. Less frequently they were observed in oak forest, woodland-meadow ecotones, xerothermic meadows, suburban areas with maquis, pastures with shrubs, olive plantations, river bank, orchards, occasionally in rocky gorges with deciduous trees. However, records from open habitats most often were located in the vicinity of trees, especially pine trees. Nests were located in soil, usually sandy, under trees, most often between roots, under small stones, less frequently under big stones. The only observed nest of C. nitidescens was located in a cracked rock wall on a roadside in oak forest under a loose piece of rock. Workers were active all day with the highest activity at dusk. Both major and minor workers were most often found on trunks and branches of coniferous trees, less often on the ground or litter.

Most of the records located in the European mainland came from areas below 700 m a.s.l. and only C. nitidescens is known exclusively from sites located between 1100 and 1700 m a.s.l. However, on Crete, specimens of C. kiesenwetteri were also found in area above 1000 m a.s.l., and the highest record comes from Trocharis peak in Lasithi province (2131 m a.s.l.). Members of the group known from Turkey manifest more alpine preferences. According to label data, the new species Camponotus schulzi was collected at the site located at an altitude of 1150–1500 m. Also C. aktaci is known almost exclusively from montane habitats located above 1000 m a.s.l.

Head, mesosoma, and gaster uniformly blackish-brown to black; metanotal groove absent; propodeum without posterior protrusion; body densely punctate, appears dull; base of scape without extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thin (PI > 1.50).

Greece: North Aegean Islands, South Aegean Islands (Dodecanese), Central Macedonia, Eastern Macedonia and Thrace; Turkey: Adana, Afyon, Antalya, Aydın, Balıkesir, Bilecik, Bursa, Çanakkale, Denizli, Diyarbakır, Elazığ, İzmir, Kırklareli, Kütahya, Manisa, Muğla, Sakarya, Uşak, and Yalova. The species was also recorded from North Macedonia (Bračko et al. 2014) and Bulgaria (Lapeva-Gjonova 2010).

Almost completely blackish-brown to black body and regularly arched (in lateral view) mesosoma cluster this species with Camponotus libanicus. At first glance both species look extremely similar and the most relevant character distinguishing both taxa is the shape of petiolar scale. Camponotus aegaeus has the scale thin (PI > 1.50) with a feebly convex anterior surface, while in C. libanicus the scale is thick (PI < 1.42) with a strongly convex anterior surface. Both species appear to be vicariant taxa with a more westerly distribution of C. aegaeus and more a easterly distribution of C. libanicus (Figs 24, 32). Indeed, niche modeling for both species show similar areas with high suitability, especially along the south coast of Turkey and Cyprus. However, unlike C. libanicus, C. aegaeus has not been recorded from the island. Solar radiation was the variable that contributed the most to the niche model of C. aegaeus.

Head and mesosoma uniformly black, gaster and legs yellowish-brown; metanotal groove absent; propodeum without posterior protrusion; body densely punctate, appears dull; base of scape without extension; whole body bears short, thin, pale, sparse and erect setae, and short appressed microsetae; petiolar scale thick.

Turkey: Adana, Bingöl, Diyarbakır, Elazığ, Malatya, Muğla.

Mostly yellowish-brown gaster and legs and short and sparse setation of head, mesosoma and gaster distinctly separates this species from other members of the Camponotus kiesenwetteri group. Temperature seasonality contributed most to the distribution model. Niche modeling showed highly suitable areas matching species known distribution at Eastern Anatolian deciduous forests but also additional areas in the central Anatolian steppe region, where there are no current occurrence records for the species. However, the westernmost record from Muğla Province is located in an area of low habitat suitability.

Head, mesosoma, and gaster uniformly black; metanotal groove present, shallow; propodeum without or with indistinct bulge-like protrusions; body densely punctate, appears dull; base of scape without extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thick.

Greece: North Aegean Islands, Crete (Heraklion), South Aegean Islands (Cyclades, Dodecanese), Peloponnese (Messinia); Turkey: Antalya, Balıkesir, Çanakkale, Denizli, Karaman, Kütahya, Muğla, and Uşak.

Density of sculpture slightly differs within this species and populations from Peloponnese and Aegean Islands are slightly more sculptured than populations from western Turkey. Camponotus boghossiani is most similar to C. nitidescens and C. schulzi and differs from them in the stronger sculpture of the mesosoma and gaster which, at first glance, appears very dull. While in both relatives the sculpture is slightly diffused and the surface is at least partly shiny. Camponotus kiesenwetteri has a similarly sculptured body surface but differs in having the posterior margin of the propodeum more or less excavate and forming well-developed, lateral dentate protrusions while in C. boghossiani the posterior margin of the propodeum is straight, without protrusions. Isolated specimens of C. kiesenwetteri, with posterior margin of propodeum very shallowly excavate, at first glance look very similar to specimens of C. boghossiani but can be easily be separated by having an antennal scape with a distinct basal extension, while in C. boghossiani the base of the antennal scape has no extension. Precipitation of the wettest quarter was the variable that contributed the most to the distribution model. High suitable areas are indicated especially along the coast of Turkey, Cyprus and Crete.

Head, mesosoma, and gaster uniformly black; metanotal groove present, shallow; propodeum with distinct dentate protrusions; body densely punctate, appears dull; base of scape with extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thick.

Greece: Attica, North Aegean Islands, South Aegean Islands (Cyclades, Dodecanese), Central Greece, Crete (Chania, Heraklion, Lasithi, Rethymno), Ionian Islands, Central Macedonia, Eastern Macedonia and Thrace, Peloponnese; Cyprus; Turkey: Balıkesir, İzmir and Muğla.

The species can be easily separated by the following combination of characters: strongly sculptured body, mesosoma with metanotal groove and posterior margin of propodeum with distinct dentate protrusions, and antennal scape with distinct basal extension. Camponotus nitidescens and C. schulzi both differ in having a partly shiny body, and C. boghossiani differs in having a propodeum without apical protrusions and an antennal scape without basal extension.

Camponotus kiesenwetteri cyprius was described by Emery (1920) based on four specimens collected from Cyprus (no data indicating a precise location). The subspecies was separated from the typical form based on the following characters: smaller body, wider mesosoma, indistinct metanotal groove, thicker petiole and shape of propodeal protrusions. The investigated type specimen agrees with the mentioned description but some of those characters overlap with intraspecific variability observed within Camponotus kiesenwetteri. Thus, we consider this species a junior synonym of C. kiesenwetteri. Nonetheless, Cyprus did not appear as a suitable region in niche modelling. Minimum temperature of coldest month was the variable that contributed most to the distribution model.

Head, mesosoma, and gaster uniformly black; metanotal groove absent; propodeum without posterior protrusion; body densely punctate, appears dull; base of scape without extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thick (PI < 1.42).

The species is known from Lebanon (André 1881, Tohmé 1969) and Cyprus: Limassol and Girne. It was also recorded from Adana, Diyarbakır, Elazığ, Hatay, Karaman, and Mersin provinces in Turkey (Forel 1913; Emery 1915; Bolu and Özgen 2018), Israel (Ionescu-Hirsch 2010) and Iran (Paknia et al. 2010). Record from Greece: Aegean Islands by Legakis (2011) is based on unpublished manuscript (Taylor and Clee 2008) and is likely based on a misidentification. Recent research on the ant fauna of the Aegean Islands has not confirmed the occurrence of this species in Greece. Additionally, the old record from İzmir in Turkey (Forel 1911) is doubtful as it was published before the description of C. aegaeus and it is located 500 km West of all the recently known localities of this species.

Camponotus libanicus belongs to the species with mesosoma evenly convex in profile, not interrupted by the metanotal groove. It is very similar to C. aegaeus and differs by having a thick petiolar scale with PI < 1.42, which in C. aegaeus is thinner at PI > 1.50. See also comments in C. aegaeaus.

In the description of C. nadimi from Lebanon, Tohmé (1969) compared this species with C. libanicus. The author noted that C. nadimi is distinctly polymorphic, while C. libanicus was considered as almost monomorphic. Additionally, C. nadimi was differentiated from C. libanicus based on the presence of emargination on the anterior margin of the clypeus and a thinner petiole. Ionescu-Hirsch (2010) was the first to suggest that the characters mentioned in the description overlap with intraspecific variability observed within populations of C. libanicus. Our observations confirm this and, additionally, samples investigated during our study consisted of distinctly polymorphic specimens. Therefore, we consider C. nadimi a junior synonym of C. libanicus. Minimum temperature of the coldest month was the variable that contributed most to the distribution model. Highly suitable areas are indicated specially along the coast of Turkey, Cyprus, Crete and Eastern Mediterranean conifer forests.

Head, mesosoma, and gaster uniformly brownish-black to black; metanotal groove present, shallow; propodeum without protrusions; body punctate, mesosoma with sculpture reduced and its lateral sides at least partially shiny; base of scape without extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thick.

Greece: Ionian Islands (Cephalonia) Peloponnese (Lakonia and Messinia), Western Greece (Aetolia-Acarnania).

Camponotus nitidescens together with C. schulzi are well distinguished from other species of the C. kiesenwetteri group in the partly reduced sculpture of the mesosoma and gaster with, at least, the lateral sides of mesosoma partly shiny. However, the sculpture is never as shiny as in members of related members of the Camponotus lateralis group. Solar radiation was the variable that contributed the most to the distribution model. Although the known distribution is restricted to the western area of the Aegean region, highly suitable areas are indicated in Crete, northeast coast of Turkey, coast of Syria and Lebanon.

Holotype : major worker (CASENT0876000): Turkey |Bozdag Mountain | 38.3277N, 28.1112E || 1150–1500 mH | 10.05.2003 | leg. A. Schulz (DBET); paratypes: 2 major workers, 5 minor workers (CASENT0876001–CASENT0876007): the same data as holotype (DBET, PW, EMTU).

Head, mesosoma, and gaster uniformly black; metanotal groove present, shallow; propodeum without protrusions; body punctate, mesosoma with sculpture reduced and its lateral sides at least partially shiny; base of scape with extension; whole body bears long, thick, pale, dense and erect setae, and short appressed microsetae; petiolar scale thick.

Measurements. Major worker (n = 3): HL: 1.827 (1.78–1.92), HW: 1.72 (1.63–1.82), SL: 1.59 (1.52–1.65), WL: 2.343 (2.27–2.44), PW: 1.22 (1.16–1.27), PRL: 0.657 (0.64–0.68), PRW: 0.43 (0.42–0.44), PTH: 0.40 (0.38–0.41), PTW: 0.293 (0.27–0.32), CI: 1.041 (1.028–1.055), SL/HW: 0.926 (0.889–0.982), PTH/PTW: 1.367 (1.281–1.413); minor worker (n = 5): HL: 1.31 (1.13–1.46), HW: 1.03 (0.94–1.29), SL: 1.297 (1.21–1.41), WL: 1.83 (1.65–2.02), PW: 0.96 (0.86–1.08), PRL: 0.58 (0.52–0.64), PRW: 0.34 (0.32–0.39), PTH: 0.397 (0.35–0.48), PTW: 0.307 (0.27–0.38), CI: 1.192 (1.132–1.241), SI: 1.185 (1.093–1.287), PI: 1.297 (1.263–1.333). Body colouration. Head, mesosoma and petiolus black, gaster from brownish-black to black. Legs brown to black, trochanters as dark as femora (Figs 1, 2, 4, 5), antennal scape brown, base and apex of scape in some specimens paler than the central part of scape, reddish-brown (Fig. 3). Head. In major workers large, trapezoidal in outline, the widest at height of eyes, distinctly narrowed anteriorly and rounded posteriorly (Fig. 7). Anterior margin of clypeus in the middle with semicircular emargination. Eyes small, placed distinctly below the mid-length of the head, 0.6 times as long as the length of tempora and 0.47 times as long as the length of genae. Scape short, slightly shorter than the width of head, with well-marked extension, without preapical constriction (Fig. 3). Funicle elongate and thin, 1.3 times as long as scape, first segment elongate, 2.3–2.4 times as long as wide on the apex, 1.4 times as long as the second segment, segments 3–6 equal in length and slightly longer than the second segment, segments 7–11 slightly shorter than the second segment. Surface of scape with fine microsculpture, very short and sparse appressed setae and 2–3 short, erect setae (Fig. 7). In minor workers head oval, the widest at height of eyes; slightly narrowed anteriorly and rounded posteriorly (Fig. 8). Anterior margin of clypeus without or with very shallow emargination. Eyes proportionally larger than in major workers; placed distinctly below the mid-length of the head, small, approximately 0.78 times as long as the length of tempora and 0.56 times as long as the length of genae. Scape short, slimmer than in major workers, 1.2–1.3 times longer than the width of head, with well-marked extension, without preapical constriction. Funicle in shape and ratio of segments similar to major workers. The surface of scape with fine microsculpture, covered with very short and sparse appressed setae, without erect setae. The whole surface of the head, in both major and minor workers, with numerous white, erect setae (Figs 2, 6). Mandibles short, dorsal surface with distinct microreticulation and partly with elongate setose punctures and elongate rugulae, matt, inner margin with one larger and 3–4 smaller teeth. Clypeus on the whole surface microreticulate and with sparse, moderately coarse, setose punctures, matt. Frontal carinae short, extending to the line connecting 1/3 length of eyes, form a regular arch, antennal sockets flat with a thin median line, microreticulate, with sparse setose punctures, dull. The area between eyes and occipital margin of head distinctly microreticulate and appears distinctly dull, microreticulation gradually diffused from dorsal to the ventral part of the head. Gena and tempora on the underside of the head with interspaces microreticulate to granulate, shiny. Mesosoma. Promesonotum regularly convex in profile with distinct metanotal groove, slightly deeper in major workers than in minor workers (Figs 2, 6). Propodeum elongate, in major workers 1.36–1.40 and in minor worker 1.50–1.60 times as long as wide; dorsal surface flat, posterior margin distinctly concave, posterior corners never forming tooth-like protrusions. The whole surface of pronotum, dorsal part of mesonotum and lateral parts of propodeum with sparse, moderately long, appressed setae, dorsal part of the whole mesosoma with long, white erect setae. Mesosoma on dorsal surface with distinct microreticulation, cells of microsculpture with shiny interspaces. On lateral sides of pronotum, microreticulation tending to form a linear sculpture of slightly shiny interspaces, sides of meso- and metathorax with a regular granulate sculpture of slightly shiny to matt interspaces. Petiole. Microreticulate but appears shiny. Petiolar squama stout, 1.26–1.33 as high as wide in lateral view, with convex anterior and flat posterior surfaces, margin with row of long, white setae (Figs 2, 6). Gaster. Tergites with sparse, short appressed setae and numerous long erect setae, with distinct regular microsculpture of transverse cells, on the whole surface more or less shiny. Legs. Moderately long, hind femora 0.8 times as long as mesosoma, hind tibiae slightly shorter than hind femora, the first segment of hind tarsi 0.8 times as long as hind femora. The whole surface of femora and tibiae with short, sparse, appressed to suberect pubescence, posterior and ventral surface of fore femora, and ventral surface of mid and hind femora with several, long erect setae, the surface of femora and tibiae appear shiny to slightly matt. Hind tibia with one long and two short apical spines and on the inner surface with a row of 3–5 short spines.

Figures 1–4. 

1, 2 Camponotus schulzi sp. nov., major worker: 1 dorsal 2 lateral 3, 4 antennal scape 3 Camponotus schulzi sp. nov. 4 Camponotus nitidescens (arrows indicate the base of scape lacking extension).

Figures 5, 6. 

Camponotus schulzi sp. nov., minor worker 5 dorsal 6 lateral.

Named after Andreas Schulz, a German amateur myrmecologist and naturalist, who extensively explored the Aegean region and collected valuable material, including the specimens of C. schulzi sp. nov.

Western Turkey: İzmir Province, Bozdağ Mts.

Figures 7, 8. 

Camponotus schulzi sp. nov., head and antennae 7 major worker 8 minor worker.

Figures 9, 10. 

Camponotus schulzi sp. nov., head sculpture 9 major worker 10 minor worker.

Camponotus schulzi sp. nov. is distinctly polymorphic, the largest major workers 1.5 times longer than the smallest minor workers. Within the C. kiesenwetteri group, together with C. boghossiani, C. kiesenwetteri, and C. nitidescens, it forms a distinct complex characterized by a shallow but distinct metanotal groove. Camponotus boghossiani and C. kiesenwetteri differ from C. schulzi in the matt body with strong and non-reduced sculpture on the whole head, mesosoma, and gaster (Figs 11–14). Additionally, C. kiesenwetteri differs in having well-developed, dentate protrusions on the posterior margin of propodeum, while in C. schulzi sp. nov. the posterior margin of the propodeum is lacking such structures; C. boghossiani differs also in the base of antennal scape lacking an extension (Fig. 4), while in C. schulzi sp. nov. the extension is well marked (Fig. 3). Camponotus nitidescens is the most similar to C. schulzi sp. nov., because both species have the mesosomal surface partly covered with weaker sculpture and especially the sides of mesosoma appear more or less shiny in both (Figs 15, 16). However, C. nitidescens has the base of the antennal scape without extension (Fig. 4) while in C. schulzi sp. nov. the extension is well marked (Fig. 3). Both species are also broadly separated geographically. Camponotus nitidescens has a narrow distribution range limited to the southern Ionian Islands, western Sterea Ellas, and Peloponnese. While C. schulzi sp. nov. was collected in western Turkey (Fig. 26). Species of the C. piceus complex of the Camponotus lateralis group at first glance can appear similar to C. schulzi sp. nov. but they differ in less-sculptured mesosoma and gaster. Especially their gaster is shinier and not as regularly reticulate or granulate as in C. schulzi sp. nov.

Figures 11–16. 

Workers in lateral view 11, 13, 15 major 12, 14, 16 minor: 11, 12 Camponotus boghossiani Forel 13, 14 C. kiesenwetteri (Roger) 15, 16 C. nitidescens Forel.

Figures 17–22. 

Workers in lateral view 17, 19, 21 major 18, 20, 22 minor: 17, 18 Camponotus aegaeus Emery 19, 20 C. libanicus André 21, 22 C. aktaci Karaman.