Heriades (Michenerella) clypeonitida Müller & Wood, 2025, sp. nov.
Creators: name: Müller, Andreas
name: Wood, Thomas J.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Megachilidae
Heriades
Heriades clypeonitida

description: Heriades (Michenerella) clypeonitida sp. nov.
Holotype. SPAIN: Segovia: Carbonero el Mayor, 2 km SW C. las Tejeras to Rio Eresma, 41.1082°N / 4.2927°W, 18.7.2021, ♀ (leg. T. Wood). Holotype deposited in the Entomological Collection of ETH Zurich.
Paratypes. BULGARIA: Blagoevgrad: Sandanski, 17.7.1966, 1♀ (leg. M. Kocourek). GREECE: Aegean Islands: Samos, Kerkis (Vigla), 1200–1440 m, 11.7.1994, 1♀ (leg. A.W. Ebmer); Thasos, Potos, 40.613°N / 24.6195°E, 17.6.2012, 1♀ (leg. M. de Courcy); Peloponnese: Mani, Kap Tenaro, 6.6.1996, 1♀ (leg. W. Arens). TURKEY: Antalya: Karamanbeli pass, 18 km S Korkuteli, 1290 m, 14.7.1994, 1♂ (leg. O. Berg). SPAIN: Segovia: Carbonero el Mayor, 2 km SW C. las Tejeras to Rio Eresma, 41.1082°N / 4.2927°W, 18.7.2021, 11♀ (leg. T. Wood). Paratypes deposited in the Entomological Collection of ETH Zurich and the private collection of T. Wood.
Diagnosis. Among the Western Palaearctic Heriades (Michenerella) species, the females of Heriades clypeonitida (Fig. 1) are recognisable by the following combination of characters: i) punctation of clypeus very scattered with interspaces reaching the diameter of several punctures (Fig. 3); ii) head slightly longer than wide (Fig. 2); and iii) absence of short and dense pilosity on the apical two thirds of the mandible (Fig. 3). The males differ by the following combination of characters: i) head about as long as wide; ii) tarsal segments 2–3 of hind leg asymmetrical; iii) hair band at apical margin of sternum 3 narrow and extending only over about one fourth of sternal width; and iv) curved apical part of gonoforceps long, finger-like, more slender than adjacent more basal part and apically with tuft of few long white hairs (Fig. 5, 6).
Description. FEMALE (Fig. 1): Body length 4.5–5.5 mm. Head: Head 1.02–1.04× as long as wide (Fig. 2). Distance between posterior margin of lateral ocellus and preoccipital margin 1.7–2.0× as long as ocellar diameter. Maximum width of genal area 0.8–1.0× as long as maximum width of compound eye. Proboscis short, reaching in repose not beyond proboscidial fossa. Second segment of labial palpus 2.0–2.2× as long as first segment and 0.46– 0.49× as long as compound eye. Mandible three-toothed and black except for preapical reddish zone, without short and dense pilosity on its apical two thirds (Fig. 3). Clypeus distinctly convex and in its apical fourth strongly bent towards labral base, its punctation fine, shallow and very scattered with interspaces reaching diameter of several punctures (Fig. 3). Paraocular area covered with dense white pilosity (Fig. 2). Punctation of supraclypeal area dense except for median zone, where interspaces may reach diameter of one to two punctures (Fig. 2). Punctation of frons very dense with interspaces rarely exceeding diameter of half a puncture, punctures slightly larger than those on supraclypeal area (Fig. 2). Antenna predominantly blackish, anterior side of flagellum more or less brownish. Antennal segments 3–5(6) shorter than wide, segments (6)7–11 as long as wide to slightly longer and segment 12 almost 2× as long as wide. Mesosoma: Parapsidal line long-linear. Punctation of scutum, scutellum and mesepisternum very dense with interspaces rarely reaching diameter of one puncture, punctures about as large as those on frons. Axilla of scutellum laterally not spined. Metanotum medially projecting to weakly spined. Basal area of propodeum at its base with very narrow and longitudinally carinate horizontal zone, which is bordered by distinct transverse carina along posterior margin. Posterior surface of propodeum adjacent to basal area polished and medially unpunctured. Tarsal segments 2–4 of fore and middle leg about as long as wide to slightly wider than long. Tibial spurs of hind leg yellowish and straight except for their apex, which is slightly bent. Metasoma: Declivous part of tergum 1 distinctly separated from horizontal part by sharp and raised carina. Punctation of terga dense with interspaces rarely exceeding diameter of one puncture, punctures half as large as those on scutum. Marginal zones of terga 1–5 with short and uninterrupted white hair bands (Fig. 1). Scopa white (Fig. 1).
MALE: Body length 5 mm. Head: Head as long as wide. Distance between posterior margin of lateral ocellus and preoccipital margin 1.7× as long as ocellar diameter. Maximum width of genal area 0.5× as long as maximum width of compound eye. Proboscis short, reaching in repose not beyond proboscidial fossa. Mandible two-toothed, black in its basal half and predominantly reddish in its apical half. Lower two thirds of face covered with dense white pilosity. Hypostomal area and adjacent base of mandible covered with dense white pilosity composed of long and distinctly plumose hairs. Punctation of frons very dense with interspaces rarely exceeding diameter of half a puncture. Antenna brownish except for predominantly blackish scapus. Antennal segments 3–4 shorter than wide, segments 5–12 as long as wide to slightly longer and segment 13 about 1.75× as long as wide. Mesosoma: Parapsidal line long-linear. Punctation of scutum, scutellum and mesepisternum very dense with interspaces rarely exceeding diameter of half a puncture, punctures about as large as those on frons. Axilla of scutellum laterally not spined. Metanotum medially weakly spined. Basal area of propodeum at its base with very narrow and longitudinally carinate horizontal zone, which is bordered by distinct transverse carina along posterior margin. Posterior surface of propodeum adjacent to basal area polished and medially unpunctured. Lower half of lateral mesepisternum and entire ventral mesepisternum rather densely covered with white pilosity. Tibia of fore and middle leg slightly widened. Posterior side of tarsal segments 1–4 of fore leg with long and plumose white hairs, which decrease in length from segment 1, where they are almost 3× as long as tarsal width, to segment 4, where they are about as long as tarsal width (Fig. 4). Tarsal segments 2–3(4) of fore, middle and hind leg asymmetrical and distinctly to slightly wider than long (Fig. 4). Ventral side of trochanter and femur of middle leg with dense brush of plumose white hairs. Basitarsus of hind leg with long white hairs, which form a rather dense brush on its ventral side. Tibial spurs of hind leg yellowish. Metasoma: Declivous part of tergum 1 distinctly separated from horizontal part by sharp and raised carina. Punctation of terga very dense with interspaces rarely reaching diameter of one puncture, punctures smaller than those on scutum. Preapical zone of tergum 6 medially with oval bump and laterally with impressed and sparsely punctured transversal groove. Tergum 7 weakly sclerotised and completely hidden under tergum 6, its apical margin medially with distinct triangular incision. Marginal zones of terga 1–3(4) with short and uninterrupted white hair bands. Sternum 1 convex and slightly wider than long. Sternum 2 medially emarginate. Sternum 3 medioapically with dense and triangular patch of long yellowish hairs largely surpassing tergal margin and covering about one fourth of sternal width. Apical margin of sternum 4 mediolaterally with two rows of six brownish bristles each, which are separated by deep triangular incision, the inner margins of which are lined with long yellowish hairs. Gonoforceps very slender, distinctly surpassing apex of penis valve and curved inwards in its apical third (Fig. 5, 6). Curved apical part of gonoforceps long, finger-like, more slender than adjacent more basal part and apically with tuft of few long white hairs (Fig. 5, 6).
Distribution. Spain and southeastern Mediterranean region (southwesternmost Bulgaria, Greece including Aegean Islands, western Turkey). The females from Spain are morphological identical with those from southeastern Europe and Turkey. However, as no males from Spain are known and females of closely related Heriades species of the subgenus Michenerella are often very similar in morphology, it cannot be excluded that the Spanish and southeastern Mediterranean populations belong to two different species. Pending the discovery of the male sex, the Spanish population is here tentatively assumed to be conspecific with the eastern populations.
Habitat. Uncultivated slope between cereals fields and the river Eresma covered with scrub including Retama (Fabaceae) on the more steeply sloping parts and with patches of Eryngium campestre on the more open parts, these swarming with H. clypeonitida. With 55 additional species recorded, a diverse bee fauna was present. Bee sampling at many Eryngium -rich sites across Ávila and Segovia provinces from 16.– 27.7.2021 did not reveal additional specimens of H. clypeonitida, suggesting that the distribution of this species might be extremely local or that Eryngium is exploited only in the absence of the normal host flowers.
Pollen hosts. In Spain, the type specimens were all observed to suck nectar on Eryngium campestre (Apiaceae), but no pollen collection was directly recorded (T. Wood, personal observation).
Etymology. The species epithet refers to the diagnostic character of the female, i.e. the punctation of the clypeus, which is very scattered giving the clypeus a very shiny appearance (lat. “nitidus” = shiny).
description: Published as part of Müller, Andreas & Wood, Thomas J., 2025, Still undescribed bees in Europe-description of nine new European osmiine bee species (Hymenoptera, Megachilidae), pp. 83-102 in Zootaxa 5631 (1) on pages 84-87, DOI: 10.11646/zootaxa.5631.1.3, http://zenodo.org/record/15326665