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

Diadegma (Nythobia) mirum sp. nov. Fig. 2 Etymology. The species epithet is derived from the Latin word mīrum, meaning “ wonderful ” – which all of Earth’s creatures ultimately are. The species epithet is an adjective in neuter nominative singular form, as the genus name Diadegma is neuter. Material examined. Holotype: Switzerland • 1 ♀; Bern, Saanen, Krinnen; 13–14 Sep. 1969; Jacques Aubert leg.; GBIFCH 02040377 (at MZL). Paratype: Sweden • 1 ♀; Kalmar län, Öland, Borgholm, Alvara Dödevi; 57.1872°N, 17.068°E; 12 Jul. 2022; Seraina Klopfstein leg.; NMB - HYMEN 0005569 (at NMB). Diagnosis. The new species is one of just five species in the genus in Europe that have the punctation on the lower mesopleuron stronger than the coriaceous background. Diadegma (Nythobia) integrator Aubert, 1970 and D. (Nythobia) rectificator Aubert, 1970 both have tergites 6 and 7 not or weakly excised, while D. (Neoangitia) aculeatum (Bridgman, 1889) has an ovipositor that is much longer than the hind tibia and shiny posterior tergites. The most similar species in Europe with rather strong punctation on the mesopleuron is D. (Nythobia) areolare (Holmgren, 1860), a species known to me only from a single specimen in the Thomson collection in Lund (marked by Jacques F. Aubert as “ TYPE!? ”). The new species can be distinguished from it by its medially orange hind tibia (ivory in D. areolare), the areolet being met by vein 2 m-cu a little apically of its middle (clearly basally in D. areolare), and by the much shorter area superomedia (which is nearly twice longer than wide in D. areolare). 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 either D. (Nythobia) areolare, D. (Nythobia) tenuipes (Thomson, 1887), or D. (Nythobia) combinatum (Holmgren, 1860). While the first of these species is already excluded above, the remaining two have the punctures on the mesopleuron at most as conspicuous as the background sculpture. From D. tenuipes, D. mirum can be further distinguished by its dark fore coxa and trochanter (orange and yellow, respectively, in D. tenuipes) and the higher POL (1.80–1.95 versus 1.25–1.45 in D. tenuipes). The new species shares both these characters with D. combinatum but has its inner eye margins almost parallel ventrally (strongly converging in D. combinatum), a lower OOL (1.05–1.10 versus 1.35–1.50 in D. combinatum), and its ovipositor evenly upcurved (nearly straight in D. combinatum). Among the group III species described since 1969, none has a medially orange hind tibia combined with an at least somewhat excised tergite 6 and dark-marked fore trochanters. However, D. (Nythobia) alpinator Aubert, 1970 meets all these criteria and was not included in the 1969 key. It was originally described as a subspecies of D. combinatum (Aubert 1970), later synonymized with that taxon by Horstmann (1973), and only thirty year later resurrected as a separate species (Horstmann 2013). The new species can be distinguished from D. alpinator by the more deeply excised tergite 6, the longer tergite 2 (1.40 versus 1.05–1.15 in D. alpinator), the more distinctly banded hind tibia, and the lower OOL (1.05–1.10 versus 1.25–1.40 in D. alpinator). Description. Measurements are based on the two females in the type series, with the value of the holotype repeated in brackets. Body 5.1–6.3 (6.3) mm. Temple in lateral view 0.75 times as long as eye, strongly and roundly constricted; OOL 1.05–1.10 (1.05), POL 1.80–1.95 (1.95); face 1.25–1.30 (1.25) times as wide as high, with coriaceous microsculpture and distinct punctures, especially in lower part, matt; malar space 0.5–0.7 (0.7) times width of mandible at base; clypeus a little rounded in profile, with weak microsculpture and distinct punctures; apical margin of clypeus somewhat impressed and reflexed as a weak lamella, margin convex in frontal view. Antenna with 26–28 (28) flagellomeres, about as long as wide or slightly longer in apical third, tapering towards apex. Pronotum above punctate on nearly smooth background, in lower half with longitudinal rugae, not bulging below mesoscutum, epomia rather long; mesoscutum coriaceous, with distinct punctures on entire surface; scuto-scutellar groove smooth; mesopleuron only weakly coriaceous, nearly smooth in most parts, with strong and dense punctures, smooth around speculum, anterior to it with longitudinal rugulae amidst the punctation; metapleuron largely smooth and with strong punctures. Fore wing 3.25–4.60 (4.60) mm, areolet quadrate, medium-sized to large, strongly petiolate above, with vein 2 m-cu meeting it a bit apically of its middle. Hindwing with nervellus nearly vertical, weakly rounded, unbroken. Hind femur 4.75–4.80 (4.80) times as long as high; hind claw not surpassing pulvillus in lateral view, with strong pecten reaching to more than half its length, a bit shorter than claw itself. Propodeum with carinae strong, coriaceous in area basalis and area externa, rugulose in area dentipara and area superomedia, with transverse rugae in area petiolaris; area basalis short, triangular, directly meeting area superomedia; area superomedia of average size, long pentagonal with lateral sides slightly converging, a bit longer than wide, posteriorly open; area petiolaris very weakly impressed medially. Metasoma laterally compressed, widest around tergite 2 or 3, coriaceous and with weak but dense punctures. Tergite 1 with small, deep glymma a bit closer to spiracle than to base, postpetiolus first rounded, then flat dorsally. Tergite 2 1.40–1.45 (1.40) times longer than wide at apex, tergites 6 and 7 deeply excised. Ovipositor sheath 0.85–0.90 (0.90) times as long as hind tibia, evenly upcurved, with notch rather distant from apex, ventral valve apparently smooth. Black; palps, mandibles except teeth, tegula, wing base, and fore trochantellus yellow; scape black; wing venation brown, pterostigma medium brown. All coxae black; trochanters and mid and hind trochantelli black at base, narrowly yellow at apex; femora light to dark orange, ventrally marked with black at least at base; fore and mid tibiae orange, mid tibia with indication of subbasal and apical brown marks, tarsi orange to brown; hind tibia on the inner side orange, on the outer ivory at base, orange medially, dark brown to black subbasally and apically; hind spurs and base of first tarsomere orange to brown, remainder dark brown. Metasoma entirely black. No host data is available for this species.