Diadegma (Nythobia) davidmarquesi Klopfstein, 2026, sp. nov.

Diadegma (Nythobia) davidmarquesi sp. nov. Fig. 1 Etymology. This species is named in honour of David Marques – outstanding naturalist, ornithologist and evolutionary biologist, and most of all esteemed colleague. His dedication to research, to the stewardship of our natural history collections, and to his family have been an inspiration to me ever since we first met. The species epithet is a masculine genitive singular noun. Material examined. Holotype: Switzerland • 1 ♀; Glarus, Linthal, Obersand, Melchplatz; 46.84°N, 8.9306°E; 2051 m a. s. l.; 19–28 Jun. 2008; Hannes Baur, Seraina Klopfstein leg.; Malaise trap # 3; GBIFCH 02040366 (at NMBE). Paratypes: • 5 ♀; [same data as holotype]; GBIFCH 02040367 –02040371 (at NMBE) • 5 ♀; [same data as holotype]; NMB - HYMEN 0005555 –0005559 (at NMB) • 1 ♀; [same locality as holotype]; 10–19 Jun. 2008; GBIFCH 02040372 (at NMBE) • 2 ♀; [same locality as holotype]; 10–19 Jun. 2008; NMB - HYMEN 0005560 –0005561 (at NMB) • 3 ♀; Graubünden, Surses, Alp Flix, Clavania; 46.5203°N, 9.6564°E; 1987 m a. s. l.; 20 Jul. – 25 Aug. 2008; Hannes Baur, Salome Steiner leg.; Malaise trap # 2; GBIFCH 02040373 –02040375 (at NMBE) • 4 ♀; [same data as previous]; NMB - HYMEN 0005562 –0005565 (at NMB) • 1 ♀; [same locality as previous]; 23–30 Jun. 2003; Hannes Baur leg.; Malaise trap # 1; NMB - HYMEN 0005566 (at NMB) • 1 ♀; [same locality as previous]; 4–20 Jun. 2008; Hannes Baur, Salome Steiner leg.; MalaiseTrap # 2; GBIFCH 02040376 (at NMBE) • 1 ♀; Graubünden, Surses, NE of Sur; 46.5242°N, 9.6342°E; 1770 m a. s. l.; 1–25 Sep. 2006; Hannes Baur, Seraina Klopfstein leg.; Malaise trap; NMB - HYMEN 0005567 (at NMB) • 1 ♀; Graubünden, Surses, Alp Flix, Lai Neir; 46.5356°N, 9.6375°E; 1920 m a. s. l.; 15–27 Jul. 2006; Hannes Baur, Seraina Klopfstein leg.; Malaise trap; NMB - HYMEN 0005568 (at NMB). Diagnosis. Diadegma davidmarquesi has a characteristic, small and posteriorly converging area superomedia, but this character can be difficult to judge without having a lot of comparative material at hand. The new species also has a strong dark mark at the base of the hind femur, which further strengthens the impression of a dark-and-light banded leg caused by the ivory hind tibia with the strong subbasal and apical bands. Such a strong darkening of the base of the hind femur otherwise only occurs in D. (Nythobia) fenestrale (Holmgren, 1860), from which the new species can be distinguished from by the shorter ovipositor (0.6–0.75 versus 0.95–1.05 in D. fenestrale), the smaller and posteriorly converging area superomedia, and the generally lower OOL (0.85–1.05 versus 1.0–1.35). Diadegma (Nythobia) semiclausum (Hellén, 1949) also often has a dark marking below on the hind femur, although it is usually rather weak. The new species can be distinguished from D. semiclausum by the dark front coxa (at most with base a bit darkened in the latter), dark scape (nearly always marked with yellow below), and the higher OOL (1.45 – 1.80 versus 1.15–1.45). Furthermore, D. davidmarquesi generally has longer antennae (24–26 flagellomeres versus nearly always 23, very rarely 24) and a longer tergite 2 (1.3–2.1 times longer than wide, versus 1.15–1.35). In Horstmann’s key (Horstmann 1969), this species runs to group III (species with deeply excised tergite 7 and ovipositor sheath shorter than hind tibia), and within the group to D. semiclausum (under the junior synonym D. eucerophagum Horstmann, 1969); see above for distinguishing features from that species. Among the group III species described after 1969, only two are similar to D. davidmarquesi in having the hind tibia ivory medially and tergite 6 not or weakly excised: Diadegma (Nythobia) hispanicum Horstmann, 1973 and D. (Nythobia) incompletum Horstmann, 1973, but both never have the fore coxa dark, never have a dark mark basoventrally on the hind femur, and the latter furthermore has the longitudinal carinae on the propodeum strongly reduced. Description. Body 5.2–6.1 (5.9) mm. Temple in lateral view 0.70–0.95 (0.85) times as long as eye, dorsally rather steeply, at mid-height of eye evenly and roundly constricted; OOL 0.85–1.05 (1.0), POL 1.4–1.8 (1.4); face 1.30–1.40 (1.35) times as wide as high, with strong coriaceous microsculpture against which punctures are disappearing, matt; malar space 0.70–0.90 (0.85) times width of mandible at base; clypeus a little rounded in profile, with weak microsculpture against which some punctures are visible; apical margin of clypeus somewhat impressed and reflexed as a weak lamella, especially laterally, margin slightly convex in frontal view. Antenna with 24–26 (26) flagellomeres, all of which longer than wide, tapering towards apex. Pronotum coriaceous above, in lower half with longitudinal rugae, not bulging below mesoscutum, epomia short; mesoscutum coriaceous, at most with indistinct punctures on lateral parts; scuto-scutellar groove smooth; mesopleuron strongly coriaceous, with a few weak punctures indicated ventrally and anteriorly, smooth around speculum, anterior to it with longitudinal rugulae; metapleuron coriaceous and slightly shiny above. Fore wing 3.6–4.4 (4.1) mm, areolet quadrate, small to medium-sized, weakly to strongly petiolate above, with vein 2 m-cu meeting it clearly apically of middle. Hindwing with nervellus nearly vertical, weakly rounded, unbroken. Hind femur 4.6–5.2 (4.9) times as long as high; hind claw not much surpassing pulvillus in lateral view, with strong pecten reaching to more than half its length, nearly as long as claw itself. Propodeum with carinae strong, coriaceous in area basalis, area externa and area superomedia, with rugae in area dentipara and strong, transverse rugae in area petiolaris; area basalis short, triangular, directly meeting area superomedial; area superomedia rather small, pentagonal with lateral sides clearly converging, shorter than to nearly as long as wide, posteriorly open to nearly closed by a transverse ruga; area petiolaris somewhat impressed medially. Metasoma laterally compressed, widest around tergite 4 or 5, coriaceous sculpture becoming weaker towards apex where it ends up rather shagreened and with minute punctures around hair roots. Tergite 1 0.6–0.7 (0.6) times as long as hind tibia, with small, deep glymma at about halfway between base and spiracle, postpetiolus first rounded, then nearly flat dorsally. Tergite 2 1.30–2.10 (1.65) times longer than wide at apex, tergite 6 not or very weakly excised, tergite 7 deeply excised. Ovipositor sheath 0.60–0.75 (0.65) times as long as hind tibia, evenly upcurved, rather thin, with notch rather distant from apex, ventral valves with minute teeth. Black; palps, mandibles except teeth, tegula, wing base, and all trochantelli light yellow; scape black; wing venation brown, pterostigma medium brown. All coxae black, fore and mid trochanters orange at base, remainder light yellow, hind trochanter black with yellow apex, all femora orange, hind femur with large black mark at base, especially ventrally, and often dorsally at apex; fore and mid tibiae orange, often ivory on outer side, mid tibia with indication of subbasal and apical brown bands, tarsi orange to brown; hind tibia on the inner side orange, on the outer ivory at base and medially, dark brown to black subbasally and apically; hind spurs and base of first tarsomere ivory, remainder dark brown. Metasoma entirely dark. No host data is available to date for this species.