Chelostoma ( Chelostoma ) kurdistanicum Müller, 2025

Müller, Andreas, Pisanty, Gideon & Dorchin, Achik, 2025, Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species, Zootaxa 5717 (3), pp. 329-369 : 352-354

Chelostoma ( Chelostoma) kurdistanicum Müller , sp. nov.

Holotype. IRAN: Kohgiluyeh and Boyer-Ahmad : Yasuj, Sarb-e Taveh, 2030 ± 600 m, 30.545°N / 51.61°E, ♂ (leg. M. Kafka). Deposited in the Entomological Collection of ETH Zurich.

Paratypes. IRAN: Ilam: Abda Man Dinar Gaouh , 1830 m, 32.915 ° N / 47.301 ° E, 12.5.2016, 2♀ (leg. M. Kafka) ; Kohgiluyeh and Boyer-Ahmad: Yasuj , Sarb-e Taveh , 2030 ± 600 m, 30.545°N / 51.61°E, 4.5.2016, 3♀, 4♂ (leg. M. Kafka) ; Likak, Bach Goland , 1640 m, 30.993 ° N / 50.148 ° E, 7.5.2016, 2♀ (leg. M. Kafka) ; Lorestan: Dorud, Lanjabad , 960 m, 33.419 ° N / 48.986 ° E, 10.5.2016, 1♀ (leg. M. Kafka) . IRAQ: Dahuk: Mount Gara , 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 2♂ (leg. D. Baiocchi) . TURKEY: Hakkari: 8 km N Oramar (= Dağlıca ), 1500 m, 10.6.1981, 1♀ (leg. K. Warncke) ; Tanin-Tanin pass, 2300 m, 19.5.1989, 1♂ (leg. K. Warncke) . Deposited in the Entomological Collection of ETH Zurich .

Additional material. IRAQ: Dahuk: Mount Gara , 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 2♂ (leg. D. Baiocchi) . TURKEY: Hakkari: Halil pass E Süvari, 1900 m, 1.6.1980, 2♂ (leg. M. Schwarz) ; 8 km N Oramar (= Dağlıca ), 1500 m, 10.6.1981, 2♀, 1♂ (leg. K. Warncke) ; Şemdinli , 1700 m, 12.6.1981, 1♀, 2♂ (leg. K. Warncke) ; Siirt: E Şirnak, 4.6.1977, 8♀, 2♂ (leg. K. Warncke) .

Diagnosis. C. kurdistanicum is similar to the other representatives of the C. mocsaryi species group. The females differ from the other species of the C. mocsaryi group by the following combination of characters: i) body length not exceeding 7 mm, ii) clypeus medially flat to slightly concave ( Fig. 52 ), iii) vertex rather short with distance between outer margins of posterior ocelli being distinctly longer than distance between anterior margin of lateral ocellus and occipital margin ( Fig. 51 ), iv) labrum on upper side almost straight over entire length, its punctate apicalmost part medially about 0.5× as long as apically wide ( Fig. 52 ) and transitioning without ledge into the impunctate more basal part, which is usually completely shagreened and laterally lacks a narrow longitudinal groove along the labral margin (only visible if labrum is fully exposed), and v) inner margin of mandible with distinct triangular tooth between base and second outermost tooth, rendering mandible three-toothed ( Fig. 53 ). The males can be distinguished from the other species of the C. mocsaryi group by the following combination of characters: i) hypostomal area with two small tubercles adjacent to hypostomal carina ( Fig. 54 ), ii) polished impunctate zone of genal area along lower margin of compound eye much narrower than width of antennal flagellum in its apical half, iii) median projection of sternum 2 in ventral view roughly triangular and anteriorly not prolonged into almost vertically projecting lamella, its anterior margin angular but not sharp and not overhanging anterior surface, and angle between anterior and ventral surface about 90 degrees in lateral view ( Fig. 57, 58 ), and iv) patches of short black thorns on sternum 3 small, roundish and separated from each other by a distance at least twice as large as maximum width of a thorn patch ( Fig. 58 ).

Description. FEMALE ( Fig. 49 ): Body length 6–7 mm. Head: Head 1.05–1.1× as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.3-1.4× as long as ocellar diameter and distance between outer margins of posterior ocelli distinctly longer than distance between anterior margin of lateral ocellus and occipital margin ( Fig. 51 ). Clypeus medially flat to slightly concave ( Fig. 52 ), its punctation dense with interspaces only rarely reaching the diameter of one puncture except medially and basally where the interspaces may reach the diameter of one and a half punctures. Apical margin of clypeus medially straight and denticulate and laterally slightly protruding. Labrum 1.5–1.7× as long as apically wide, basally flat, apically truncate to very shallowly emarginate and in lateral view upper side almost straight over entire length; its punctate apicalmost part medially about 0.5× as long as apically wide and transitioning without ledge into impunctate more basal part ( Fig. 52 ); its impunctate basal part usually completely shagreened, laterally without narrow polished longitudinal groove along labral margin ( Fig. 52 ). Mandible three-toothed, its inner margin with distinct triangular tooth between base and second outermost tooth ( Fig. 53 ). Proboscis short ( Fig. 49 ), not reaching till base of fore coxa when folded; second segment of labial palpus 2.75–3.1× as long as first segment and about 0.5× as long as compound eye. Mesosoma : Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.75- 0.9× as long as metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished to imperceivably shagreened transverse ridge. Metasoma: Terga 2–3 not or only weakly constricted at base. Marginal zones of terga 1–4 with short and dense white hair bands ( Fig. 49 ), which are not interrupted in fresh specimens. Scopa white, its hairs not plumose ( Fig. 49 ).

MALE ( Fig. 50 ): Body length 6.5–8 mm. Head: Head about as long as wide. Genal area along lower margin of compound eye with polished impunctate zone, which is distinctly narrower than width of antennal flagellum in its apical half. Distance between posterior margin of lateral ocellus and occipital margin 1.4–1.5× as long as ocellar diameter. Hypostomal area with two small tubercles adjacent to hypostomal carina ( Fig. 54 ). Proboscis short ( Fig. 50 ), not reaching till base of coxa of fore leg when folded; second segment of labial palpus about 3× as long as first segment and 0.5–0.6× as long as compound eye. Antennal segments 3–13 longer than wide, anterior side and to different degrees also posterior side of segments (4)5–12(13) yellowish-brown to yellowish-red. Mesosoma : Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.75- 1× as long as metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished to imperceivably shagreened transverse ridge ( Fig. 55 ). Tibial spur of fore leg apically truncate to almost imperceivably emarginate. Metasoma: Marginal zones of terga 1–5 with rather short and dense white hair bands ( Fig. 50 ), which are widely interrupted on terga 1–3. Terga 2–3 basally not or only weakly constricted. Tergum 7 basally with roundish pit and apically with two teeth, which are narrow and parallel-sided, slightly diverging, about 2× as long as basally wide, apically weakly rounded and separated from each other by a semicircular incision, which is maximally 2.5–3× as wide as tooth width ( Fig. 56 ). Ventral base of apical teeth of tergum 7 with large backwardly and inwardly directed tooth-like projection, the tip of which is clearly visible when tergum 7 is viewed from above ( Fig. 56 ). Apical margin of sternum 1 medially shallowly emarginate. Median projection of sternum 2 in ventral view roughly triangular in shape with anteriorly rounded tip, medially slightly impressed and densely punctate and laterally surrounded by narrow impunctate and polished zone ( Fig. 58 ); in lateral view, anterior margin of median projection angular but neither prolonged nor overhanging anterior surface of median projection, and angle between anterior and ventral surface almost 90 degrees ( Fig. 57 ). Sternum 3 with well-developed and long whitish pilosity and medioapically with two small roundish patches of short black thorns, which are separated from each other by a distance of at least twice as large as the maximum width of a thorn patch ( Fig. 58 ); apical margin of sternum 3 medially slightly emarginate and with short membraneous appendage that is medially divided into two lobes. Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is apically curled downwards. Apical margin of sternum 5 with a single row of long and thin yellowish-white bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, almost hairless, very sparsely punctate and medially impressed.

Distribution. Southeastern Turkey, northern Iraq, western Iran ( Fig. 74 ).

Pollen hosts. Three pollen loads from two different localities exclusively consisted of an identical type of monocotyledonous pollen that could not be distinguished from pollen of Ornithogalum ( Asparagaceae ) at a magnification of 400×, suggesting that C. kurdistanicum is oligolectic on Ornithogalum as is the closely related species C. mocsaryi (see below). This assumption is supported by the fact that C. kurdistanicum was collected near Yasuj in eastern Iran together with C. mocsaryi at the very same place and date, which makes it probable that Ornithogalum served as pollen host for both species.

Nesting biology. Unknown.

Etymology. The species epithet refers to the distribution area, which includes large parts of Kurdistan, the historical settlement area of the Kurds.

Figures

FIGURE 74. Distribution of the eight Chelostoma species newly described in the present publication: C. dolichocephalum (violet), C. kurdistanicum (orange), C. levantense (white), C. meronense (dark blue), C. miripalpum (light blue), C. negevense (red), C. ornithogali (yellow) and C. scabiosae (green). Made with Natural Earth (ww w.naturalearthdata.com).

FIGURES 49–58. Chelostoma kurdistanicum: 49: Female, 50: Male, 51: Vertex of female, 52: Labrum and clypeus of female in ventral view, 53: Mandible of female. 54: Hypostomal area of male, 55: Basal area of propodeum of male, 56: Terga 5–7 of male, 57: Sternum 2 of male in lateral view, 58: Sterna 2–3 of male.