Osmia (Helicosmia) sardoa Müller & Wood, 2025, sp. nov.

Osmia (Helicosmia) sardoa sp. nov. Holotype. ITALY: Sardinia: Cala Fuili, 40.256°N / 9.624°E, 30 m, 28.4.2018, ♀ (leg. D. Bénon). Holotype deposited in the Entomological Collection of ETH Zurich. Diagnosis. The females of Osmia sardoa (Fig. 44), which have a body length of 9–10 mm, are morphologically very similar to those of O. leaiana, both differ by the following characters from closely related O. (Helicosmia) species: i) apical margin of clypeus medially with two or rarely three teeth, which usually enclose two narrow tufts of yellowish hairs (Fig. 46); ii) base of mandible supramedially with distinct polished bump; and iii) interspaces between punctures of posterior surface of propodeum distinctly shagreened. The females of O. sardoa (Fig. 44) can easily be separated from those of O. leaiana by the following characters: i) pilosity of head, mesosoma and terga foxy red and of same colour as metasomal scopa (Fig. 44, 45; pilosity whitish to yellowish and of distinctly lighter colour than orange metasomal scopa in O. leaiana); ii) marginal zones of terga 1–5 with dense foxy-red pilosity forming distinct hair bands (Fig. 45; marginal zones with very sparse whitish to yellowish pilosity not forming distinct hair bands in O. leaiana); iii) pilosity of tergal discs 2–4 longer with longest hairs distinctly longer than tarsal segment 3 of hind leg (pilosity shorter with longest hairs about as long as tarsal segment 3 of hind leg in O. leaiana); and iv) metallic sheen of body more extended: central face, mesepisternum and scutellum slightly green metallic and clypeus, gena vertex, scutum, propodeum and terga partly weakly purple metallic (metallic sheen usually limited to terga, which are partly weakly green metallic in O. leaiana). The male of O. sardoa is unknown. Description. Except for the characters given in the diagnosis, the females of O. sardoa are morphologically identical to those of the widespread and well-known O. leaiana. Therefore, no detailed description of the new species is given here. Distribution. Sardinia. Etymology. The species epithet refers to the occurrence of the species on Sardinia (lat. “sardous” = Sardinian).