Camponotus bakhtiariensis, Salata & Khalili-Moghadam & Borowiec, 2020

Salata, Sebastian, Khalili-Moghadam, Arsalan & Borowiec, Lech, 2020, Review of the Camponotus samius complex (Hymenoptera: Formicidae) in the Turano-Balkan region, with the description of a new species from Iran, Zootaxa 4763 (4), pp. 545-562 : 548-553

Camponotus bakhtiariensis sp. nov.

Figs 1–9

Type material: Holotype major worker (CASENT0872760): IRAN, Chaharmahal Va | Bakhtiari , Koohrang | Dashte laleh, 2400 m || 32.5884 / 50.2002 | 25 V 2017 | A. Khalili-Moghadam || Collection L. Borowiec | Formicidae | LBC-IR00068 ( DBET-MNHW); four major, two medium, and three minor worker paratypes (CASENT0872761– CASENT0872769): the same data as holotype ( MHNG, MSNG, MNHW-DBET).

Diagnosis. Hind tibia and scape with decumbent to suberect pilosity but without additional erect setae; gena with numerous erect setae; mesosoma, head, and gaster in major and minor workers uniformly black to dark brown; gaster in major and minor workers without brighter colouration on its basal part; pilosity on gaster sparse and short, distance between microsetae is equal to full or two lengths of microsetae; erect setae sparse; petiolar squama in both major and minor workers slim with only slightly convex anterior surface.

Description. Measurements. Major worker (n = 6): HL: 3.07 (2.63–3.28), HW: 2.91 (2.35–3.12), SL: 2.58 (2.40–2.70), WL: 3.88 (3.60–4.05), PW: 1.92 (1.73–2.00), PRL: 1.85 (1.67–2.03), PRW: 0.95 (0.82–1.06), PTH: 1.33 (1.20–1.40), PTW: 0.39 (0.37–0.41), CI: 1.06 (1.03–1.12), SI: 0.89 (0.86–1.02), PI: 3.40 (3.24–3.58). Medium worker (n = 2): HL: 2.41 (2.35–2.47), HW: 2.07 (1.97–2.17), SL: 2.39 (2.37–2.42), WL: 3.49 (3.30–3.67), PW: 1.64 (1.60–1.67), PRL: 1.44 (1.40–1.48), PRW: 0.98 (0.92–1.03), PTH: 1.17 (1.09–1.24), PTW: 0.34 (0.32–0.35), CI: 1.17 (1.14–1.19), SI: 1.16 (1.12–1.20), PI: 3.50 (3.11–3.88). Minor worker (n = 3): HL: 2.16 (1.96–2.30), HW: 1.67 (1.46–1.83), SL: 2.22 (2.13–2.33), WL: 3.19 (2.97–3.33), PW: 1.47 (1.34–1.59), PRL: 1.48 (1.38–1.68), PRW: 0.62 (0.58–0.64), PTH: 1.05 (0.96–1.20), PTW: 0.34 (0.30–0.36), CI: 1.30 (1.26–1.34), SI: 1.34 (1.27–1.46), PI: 3.13 (2.74–3.33).

Body colouration. Head, mesosoma, petiolar scale and gaster black. Legs in major worker mostly dark brown to black only tarsi slightly paler coloured with first segment brown and distal segments reddish-brown, trochanters as dark coloured as femora ( Figs 1, 2 , 5, 6 ), in minor workers legs brown with slightly paler coloured tarsi; mandibles reddish-brown in major workers and yellowish-red to red in minor workers; antennal scape in both major and minor workers black, only basal knob yellowish and extreme base of scape reddish-brown ( Figs 3, 4 ). Basal 2-3 segments of funiculus brown to dark brown basally and reddish brown apically, segments 4-11 gradually paler from reddish to yellowish-red ( Figs 3, 4 ). Head. In major workers large, trapezoidal in outline, the widest close to upper margins of eyes, distinctly narrowed anteriad and rounded posteriad ( Fig. 3 ), posterior margin almost straight. Anterior margin of clypeus in the middle without or with very shallow emargination. Eyes small, placed distinctly before mid-length of head, 0.43 times as long as length of tempora and approximately 0.67 times as long as length of genae. Scape short, 0.86 times as long as width of head, at apex 1.8 times wider than at base, without basal extension and without preapical constriction ( Fig. 3 ). Funiculus moderately elongate and thin, 1.4 times as long as scape, first segment elongate, three times as long as wide on apex, 1.2 times as long as second segment, segment 3 almost equal in length and segments 4-6 slightly shorter than segment 3, segments 7-10 gradually shorter than second segment, segment 11 elongate, 2.7 times as long as wide. Surface of scape with fine microsculpture, very short and sparse adherent setae and on dorsal surface with row of suberect setae, without erect seate. Whole surface of head with numerous long, erect setae, also on clypeus, gena, in temporal parts and ventral surface. In minor workers head elongate, parallel sided, softly rounded posteriad ( Fig. 8 ). Anterior margin of clypeus without or with very shallow emargination. Eyes proportionally larger than in major worker, placed distinctly before mid-length of head, small, approximately 0.48 times as long as length of tempora and approximately as long as length of genae. Scape elongate, slimmer than in major worker, 1.4-1.5 times longer than width of head, at base 0.7 times as wide as in apex, straight, without and without preapical constriction. Funiculus in shape and ratio of segments similar as in major worker. Surface of scape with fine microsculpture, covered with very short and sparse adherent setae, and on dorsal surface with row of suberect setae but without erect setae. Whole surface of head with numerous long, erect setae, also on clypeus, gena, in temporal parts and ventral surface ( Figs 2 , 6 ).

Medium workers have head with characters intermediate between major and minor workers. All workers have mandibles short, dorsal surface at base with distinct microreticulation and on whole dorsal surface with longitudinal ridges and setose punctures, dull, inner margin with one large and 3-4 moderately large teeth. Clypeus on whole surface microreticulate and with sparse, moderately coarse, setose punctures, in minor workers appearing slightly shiny in major workers dull. Median carina distinct on whole clypeal length, anterior margin crenulate ( Figs 7, 8 ). Frontal carinae short, extending at most to half-length of eye. Whole surface of head distinctly microreticulate and with small, sparse, setose punctures, appears distinctly dull, in major workers slightly duller than in minor workers. Mesosoma. In both major and minor regularly convex in profile with distinct suture between pronotum and mesono- tum, and between mesonotum and propodeum, in major worker propodeal angle in profile almost straight in minor worker softly rounded ( Figs 2 , 6 ). In lateral view propodeum across middle only slightly longer than mesonotum and in major workers as long as wide, in minor worker 1.43 times as long as wide. Whole surface of pronotum, dorsal part of mesonotum and propodeum covered with dense, very long erect setae ( Figs 2 , 6 ). Petiolar squama thin in profile, with moderately convex anterior surface, in both minor and major workers approximately twice as high as wide in lateral view, at top with several long, yellow setae ( Fig. 9 ). Mesosoma on whole surface with distinct microreticulation and small, sparse punctation, on dorsal part as dull as on head, on sides slightly less dull than on head, especially in minor workers background of microreticulation slightly shiny. Petiolar scale. Microreticulate but appears more or less shiny. Gaster. On dorsum with numerous, long erect setae and sparse, short adherent setae, with distinct regular microsculpture, in major workers microsculpture only partly forms transverse cells or striation, in minor workers microsculpture forms distinct transverse striation. In major workers gaster appears dull in minor workers more or less shiny. Legs. Long, hind femora approximately 0.83 times as long as mesosoma, hind tibia as long as hind femora, first segment of hind tarsi approximately 0.73 times as long as hind femora. Lateral surface of hind tibia in major workers flat with more or less marked lateral channel, in minor workers flattened but without channel. Lateral and dorsal surface of femur and tibia with short, sparse, suberect pubescence but without erect setae, surface of femur and tibia microreticulate, appears dull in major workers and more or less shiny in minor workers. Hind tibia with one very long and 4-5 short apical spines and on inner surface with a row of 9-12 short spines.

Distribution. Southwestern Iran: Chaharmahal va Bakhtiari Province.

Biological notes and habitat description. Koohrang County is located in the northern part of the Chaharmahal Va Bakhtiari province. The county is surrounded by the Zagros Mountains, one of the two largest mountain ranges of Iran. It has an alpine climate. Dashte laleh, the type locality, is located on a small plateau, 3600 hectares and 2000-2600 m above sea level, and in May is predominantly overgrown by Snake’s head ( Fritillaria imperialis ). Other common plants recorded from this area are Milkvetch ( Astragalus spp.), Persian shallot ( Allium stipitatum ), and kheshk ( Daphne mucronata ). The biology of the species is unknown. The only available material was collected from a nest which was found under a rock in a grazing area.

Comments. Camponotus bakhtiariensis sp. nov. belongs to the complex of Turano-Balkan members of the Camponotus samius complex and is distinctly polymorphic, the largest major workers are 1.4 times longer than the smallest minor workers. It differs from C. festai by the lack of additional erect setae on the scape and hind tibia; from C. ionius by the uniformly black mesosoma and presence of erect setae on the genae; from C. samius in the uniformly black mesosoma and lack of brighter colouration of the basal part of gaster. Camponotus laconicus , an allopatric species from Greece, is the most similar. Camponotus bakhtiariensis sp. nov. has distinctly sparser and shorter setae and microsetae on the gaster, the petiolar node, in both major and minor workers, is slim with a slightly convex anterior surface, and the legs of minor workers are entirely dark brown. In the Turano-Balkan region there are other large Camponotus species of the subgenus Tanaemyrmex that are entirely or almost entirely black. These are not in the C. samius complex and differ in the absence of erect pubescence on scape and tibia.

Figures

FIGURES 1–2. Camponotus bakhtiariensis sp. nov., major worker, holotype (CASENT0872760): 1—dorsal, 2—lateral (scale bar = 2 mm).

FIGURES 3–4. Camponotus bakhtiariensis sp. nov., head and antennae: 3—major worker (CASENT0872760), 4—minor worker (CASENT0872761) (scale bar = 1 mm).

FIGURES 5–6. Camponotus bakhtiariensis sp. nov., minor worker, paratype (CASENT0872761): 5—dorsal, 6—lateral (scale bar = 2 mm).

FIGURES 7–8. Camponotus bakhtiariensis sp. nov., head sculpture: 7—major worker (CASENT0872760), 2—minor worker (CASENT0872761).

FIGURES 9–10. Petiolar scale: 9—Camponotus bakhtiariensis sp. nov., 10—Camponotus laconicus Emery.