Chelostoma ( Chelostoma ) negevense 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 : 355-357

Chelostoma ( Chelostoma) negevense Müller , sp. nov.

Holotype. ISRAEL AND PALESTINE: Southern District : Lakhish, 20.3.2013, ♂ (leg. T. Shapira). Deposited in the Steinhardt Museum of Natural History Tel Aviv.

Paratypes. ISRAEL AND PALESTINE: Southern District : Har Horesha, 30 ° 36′N / 34 ° 31′E, 6.4.2005, 1♂ (leg. L. Friedmann). Deposited in the Entomological Collection of ETH Zurich .

Diagnosis. C. negevense is similar to the other representatives of the C. mocsaryi species group.While the females are not yet known, the males differ from the other species of the C. mocsaryi group by the following combination of characters: i) hypostomal area with two tooth-like projections adjacent to hypostomal carina ( Fig. 60 ), ii) polished impunctate zone of genal area along lower margin of compound eye narrower than width of antennal flagellum in its apical half ( Fig. 61 ), iii) upper teeth of tergum 7 basally slightly constricted, medially weakly widened and apically slightly curved, largely hiding lower teeth when seen from above ( Fig. 62 ), iv) median projection of sternum 2 in ventral view half-elliptical and anteriorly not prolonged into almost vertically projecting lamella, its anterior margin sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees in lateral view ( Fig. 63, 64 ), v) patches of black thorns on sternum 3 small, roundish and separated from each other by distance several times larger than maximum width of thorn patch ( Fig. 64 ), and vi) apical part of gonoforceps laterally distinctly flattened, its apex almost linear when seen from behind ( Fig. 65 ).

Description. FEMALE: Unknown.

MALE ( Fig. 59 ): Body length 8.5–9.5 mm. Head: Head 0.95–1× as long as wide. Genal area along lower margin of compound eye with slightly impressed and more or less polished impunctate zone, which is narrower than width of antennal flagellum in its apical half ( Fig. 61 ). Distance between posterior margin of lateral ocellus and occipital margin 1.5–1.6× as long as ocellar diameter. Hypostomal area with two tooth-like projections arising laterally to hypostomal carina ( Fig. 60 ). Proboscis short, not reaching till base of coxa of fore leg when folded. Antennal segments 3(4) and 13 longer than wide, segments (4)5–12 about as long as wide, anterior side and to large extent also posterior side of segments (3)4–13 yellowish-red. Mesosoma : Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.6–0.7× 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. 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. 59 ), which are widely interrupted on terga 1–3. Tergum 7 basally with roundish pit and apically with two teeth, which are basally slightly constricted, medially weakly widened, apically tapering, 1–1.75× as long as basally wide and separated from each other by a semicircular incision, which is maximally 1.5–2× as wide as maximum tooth width ( Fig. 62 ). Ventral base of apical teeth of tergum 7 with large backwardly directed tooth-like projection, the tip of which is largely hidden by upper tooth when viewed from above ( Fig. 62 ). Apical margin of sternum 1 medially shallowly emarginate. Median projection of sternum 2 in ventral view half-elliptical in shape with rounded anterior margin, medially slightly impressed, sparsely punctate and weakly shagreened and laterally surrounded by largely impunctate and polished to weakly shagreened zone ( Fig. 64 ); in lateral view, anterior margin of median projection sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees ( Fig. 63 ). Sternum 3 with well-developed and long whitish pilosity and medioapically with two small and roundish patches of short black thorns, which are separated from each other by a distance several times larger than the maximum width of the thorn patch ( Fig. 64 ); 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, largely impunctate and medially impressed. Apical part of gonoforceps laterally distinctly flattened, its apex almost linear when seen from behind ( Fig. 65 ).

Distribution: Central to southern Israel ( Fig. 74 ).

Pollen hosts. Due to the very close (morphological) relationship with C. kurdistanicum and C. ornithogali , which are probably specialized on flowers of Ornithogalum ( Asparagaceae ) as is C. mocsaryi from the same species group, C. negevense is expected to also restrict pollen collection to this plant genus. In fact, three Ornithogalum species are known to occur in the southernmost Negev near the Egyptian border ( Danin & Fragman-Sapir 2016), where the paratype male has been collected.

Nesting biology. Unknown.

Etymology. The species epithet refers to the occurrence in the Negev in southern Israel.

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 59–65. Chelostoma negevense: 59: Male, 60: Hypostomal area of male, 61: Genal area of male, 62: Terga 5–7 of male, 63: Sternum 2 of male in lateral view, 64: Sterna 2–3 of male, 65: Apices of genitalia of male (in centre of figure).