Hoplitis (Hoplitis) heliotropii Muller 2026, sp. nov.

Hoplitis (Hoplitis) heliotropii Müller, sp. nov. Holotype. SAUDI ARABIA: Riyadh: 20 km W Huraymila, 25.151°N / 45.929°E, 800 m, 25.3.2025, ♀ (leg. M. Halada). Deposited in the Entomological Collection of ETH Zurich. Paratypes. SAUDI ARABIA: Riyadh: Riyadh, King Saudi University Campus, 24.633031°N / 46.716358°E, 9.2.2015, 2♂ (leg. M. Shebl); Riyadh, Derab, Agricultural Research Station, 24.488222°N / 46.619850°E, 12.2.2015, 1♀ (leg. M. Shebl); S Riyadh, 24.425°N / 46.653°E, 6.3.2024, 1♂ (leg. M. Halada); Ulya, 100 km NW Riyadh, 25.281°N / 46.021°E, 9.3.2024, 1♂ (leg. M. Halada); Al Hair SE Riyadh, 24.392°N / 46.793°E, 520 m, 24.3.2025, 1♂ (leg. M. Halada). Deposited in the Entomological Collection of ETH Zurich. Diagnosis. Hoplitis heliotropii belongs to the subgenus Hoplitis. Within this subgenus, it is a member of the H. adunca species group as shown by the presence of a submarginal carina along the (latero)apical margin of sternum 6 in the female and by the apically rounded, truncate or only shallowly emarginate tergum 7 in the male. The 6.5–7 mm long female of H. heliotropii (Fig. 1) differs from all other species of the H. adunca group by the long and apically curved bristles that cover the first and the second segment of the labial palpus (Fig. 4, 5, 36). Similar bristles on the labial palpus also occur in the females of H. (Hoplitis) persica and H. (Hoplitis) premordica, which belong to the H. persica species group. The species of this group differ from H. heliotropii by the absence of a submarginal carina along the (latero)apical margin of sternum 6 and by the two- rather than four-segmented labial palpus, which represents a unique character among the osmiine bees. Additional characters of the female of H. heliotropii are i) the strongly convex clypeus, which is laterally densely punctate with interspaces hardly exceeding the diameter of half a puncture and medially crossed by an unpunctured longitudinal line of varying length (Fig. 3), ii) the equal length of the first and the second segment of the labial palpus, iii) the reddish coloured anterior (and partly also posterior) side of the antennal segments 4–11, iv) the largely truncate apical margin of the tibial spur of the fore leg with a barely recognizable tiny tooth (Fig. 6), v) the yellowish-white, long, slender and straight hind tibial spurs, whose apex is only very weakly curved, vi) the distinctly reddish coloured marginal zone of the terga 1-5, and vii) the sparse, appressed and whitish pilosity covering tergum 6. The 5.5–7 mm long male of H. heliotropii (Fig. 2) is characterized by the combination of the following four characters: i) first segment of the labial palpus 0.85–0.95× as long as the second segment, ii) apical margin of the tibial spur of the fore leg with a tiny tooth, which is not longer than basally wide and often barely recognizable in worn specimens, iii) lateral lobes of the bilobed membraneous appendage of sternum 6 densely haired, slightly longer than wide and separated from each other by a deep triangular incision (Fig. 8), and iv) gonoforceps abruptly bent inwards and downwards in its apical third (Fig. 9). Additional characters of the male are v) the presence of single long hairs on the ventral side of the first (and less pronounced also of the second) segment of the labial palpus, vi) the simple antennal flagellum consisting of regularly cylindrical segments, which are about as long as wide except for segments 12 and 13, which are slightly and distinctly longer than wide, respectively (Fig. 7), vii) the orange coloured anterior (and largely also posterior) side of the antennal segments (3)4–12(13) (Fig. 7), and viii) the distinctly reddish coloured marginal zone of the terga 1–6. Description. FEMALE (Fig. 1): Body length 6.5-7 mm. Head: Head about 0.85× as long as wide. Distance between posterior margin of lateral ocellus and preoccipital margin 1.05–1.15× as long as ocellar diameter. Maximum width of genal area about 0.5× as long as maximum width of compound eye. Clypeus strongly convex, laterally densely punctate with interspaces hardly exceeding the diameter of half a puncture and medially crossed by a narrow and unpunctured longitudinal line of varying length (Fig. 3); its apical margin denticulate. Mandible three-toothed and largely black. Pilosity of frons, supraclypeal area, paraocular area and gena white, rather long, moderately dense and suberect to partly appressed on supraclypeal and paraocular area; pilosity of basal half of clypeus long, sparse and semierect to erect, of apical half rather dense, suberect to appressed and distinctly surpassing clypeal margin (Fig. 3). First and second segment of labial palpus equally long and covered with long and apically curved bristles (Fig. 4, 5, 36). Anterior (and partly also posterior) side of antennal segments 4–11 reddish coloured. Antennal segment 3 about 1.25× as long as wide. Mesosoma: Parapsidal line long-linear. Punctation of scutum, scutellum and mesepisternum dense with interspaces not exceeding the diameter of half a puncture to one puncture. Basal area of propodeum shagreened. Pilosity of mesosoma whitish. Tegula yellowish-brown to yellowish-red except for black inner and anterior margin; its anterior half and inner margin moderately densely punctured, its posterior half almost unpunctured. Stigma and veins of fore wing (dark) brown to black. Apical margin of tibial spur of fore leg largely truncate with a barely recognizable tiny tooth (Fig. 6). Tibial spurs of hind leg yellowish-white, long, slender, largely straight and apically only very weakly curved. Pilosity of inner surface of basitarsus of hind leg yellowish-white. Metasoma: Punctation of tergal discs 2–4 medially rather fine and sparse with interspaces reaching the diameter of up to two to three punctures. Punctation of terga 5–6 denser with interspaces rarely exceeding the diameter of one puncture. Marginal zone of terga 1–5 distinctly reddish coloured. Terga 1–4(5) with short white hair bands, which are medially not interrupted in fresh specimens (Fig. 1). Longest erect hairs on median half of tergum 1 as long as maximal length of lateral hair tuft. Tergum 6 covered with sparse, appressed and whitish pilosity. Sternum 6 medioapically not prolonged into distinct spine and laterally with low and sharp submarginal carina. Scopa whitish. MALE (Fig. 2): Body length 5.5–7 mm. Head: Head about 0.75× as long as wide. Distance between lateral ocellus and preoccipital margin about 1.3× as long as ocellar diameter. Maximum width of genal area 0.5–0.6× as long as maximum width of compound eye. Mandible two-toothed and of black colour except for dark reddish-brown apical teeth. Apical margin of clypeus denticulate. Face and gena including ventral side covered with dense white pilosity, which is partly appressed on supraclypeal and paraocular area. First segment of labial palpus 0.85–0.95 × as long as second segment. Ventral side of first (and less pronounced also of second) segment of labial palpus with single long hairs. Flagellum of antenna simple and consisting of regularly cylindrical segments, which are about as long as wide except for segments 12 and 13, which are slightly and distinctly longer than wide, respectively (Fig. 7). Anterior (and largely also posterior) side of antennal segments (3)4–12(13) orange coloured (Fig. 7). Mesosoma: Parapsidal line long-linear. Punctation of scutum, scutellum and mesepisternum dense with interspaces rarely exceeding the diameter of one puncture except for central zone of scutum and scutellum, where punctation is slightly more scattered. Basal area of propodeum shagreened. Pilosity of mesosoma whitish. Tegula yellowish-brown to yellowish-red except for black inner margin, its anterior half fine and sparsely punctured, its posterior half impunctate. Stigma and veins of fore wing yellowish-brown to brown. Apical margin of tibial spur of fore leg with tiny tooth, which is not longer than basally wide and often barely recognizable in worn specimens. Tibial spurs of hind leg yellowish-white, slender, largely straight and apically only very weakly curved. Metasoma: Punctation of tergal discs 2–4 medially rather fine and sparse with interspaces reaching the diameter of up to two to three punctures. Punctation of terga 5–6 denser with interspaces rarely exceeding the diameter of one and a half punctures. Marginal zone of terga 1–6 distinctly reddish coloured. Marginal zone of terga 1–5 with short white hair bands, which are not interrupted in fresh specimens (Fig. 2). Protruding median part of apical margin of tergum 6 crenulate and/or with shallow to rather deep median emargination. Tergum 6 laterally with distinct narrowly triangular tooth. Tergum 7 apically evenly rounded (rarely with very shallow median emargination), its lateral margin ventromedially with small angular projection. Apical margin of sterna 1–4 almost straight to medially very slightly emarginate and beset with rather long and sparse whitish pilosity, which is shortest on sternum 4. Apical margin of sternum 5 slightly rounded (rarely with very shallow median emargination) and almost hairless (Fig. 8). Marginal zone of sterna 2–5 reddish coloured and usually with fine and rather dense punctation, distinctly contrasting with the very sparse punctation of tergal discs 3–5 (Fig. 8). Sternal discs 2–5 with medially narrowed and on sternum (4)5 interrupted transversal swelling (Fig. 8). Sternum 6 at base with pair of large translucent flaps (Fig. 8). Lateral lobes of bilobed membraneous appendage of sternum 6 densely haired, slightly longer than wide and separated from each other by a deep triangular incision (Fig. 8). Gonoforceps abruptly bent inwards and downwards in its apical third (Fig. 9). Distribution. Known so far only from Riyadh province in central Saudi Arabia (Fig. 10). Etymology. The species epithet refers to the boraginaceous genus Heliotropium, which is an important host plant of H. heliotropii