6 urn:lsid:arphahub.com:pub:DE333E49-E4EE-5693-9BEF-D446E6301C98 urn:lsid:zoobank.org:pub:55528528-5C97-4D79-A718-8B3D153B37CC Journal of Hymenoptera Research JHR 1070-9428 1314-2607 Pensoft Publishers 10.3897/jhr.99.188661 188661 Research Article Braconidae Systematics Americas Two new species of the subgenus Aliolus Say of the genus Eubazus Nees (Hymenoptera, Braconidae, Brachistinae) from the United States Yan Cheng-jin ycj0685@163.com https://orcid.org/0000-0001-5723-9635 1 Zu Zhenhua 1 van Achterberg Cornelis https://orcid.org/0000-0002-6495-4853 2 Pan Sufeng 1 Johnson Norman F. johnson.2@osu.edu https://orcid.org/0000-0003-1691-5187 3 Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology, Wenzhou 325006, China Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology Wenzhou China https://ror.org/0122fj965 Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China Institute of Insect Sciences, Zhejiang University Hangzhou China https://ror.org/00a2xv884 Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 1315 Kinnear Road, Columbus, Ohio 43212, USA Department of Evolution, Ecology and Organismal Biology, The Ohio State University Columbus United States of America https://ror.org/00rs6vg23

Corresponding authors: Cheng-jin Yan (ycj0685@163.com); Norman F. Johnson (johnson.2@osu.edu)

Academic editor: Eduardo Shimbori

 2026 11 09 2026 99 995 1008 A9B6161F-B6BA-5450-B326-E68832C970D8 92F1A12F-4EA8-466A-A63F-C0FD9E6F0919 22750842 13 02 2026 28 08 2026 Cheng-jin Yan, Zhenhua Zu, Cornelis van Achterberg, Sufeng Pan, Norman F. Johnson This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. https://zoobank.org/92F1A12F-4EA8-466A-A63F-C0FD9E6F0919

Two new species belonging to the subgenus Aliolus Say, 1836 of the genus Eubazus Nees, 1812 (Hymenoptera, Braconidae, Brachistinae) from the Nearctic region are described and illustrated, Eubazus (Aliolus) confragosus Yan, sp. nov. and Eubazus (Aliolus) rhyssoeubazus Yan, sp. nov. An updated key to the Nearctic species of the subgenus Aliolus is provided.

 braconid wasps Nearctic region new species parasitoids This research was supported by the China Scholarship Council (201908330023) and Wencheng County Science and Technology Plan Project (2025NKY12). Citation

Yan C-jin, Zu Z, van Achterberg C, Pan S, Johnson NF (2026) Two new species of the subgenus Aliolus Say of the genus Eubazus Nees (Hymenoptera, Braconidae, Brachistinae) from the United States. Journal of Hymenoptera Research 99: 995–1008. https://doi.org/10.3897/jhr.99.188661

 Introduction

The genera Eubazus Nees, 1812 and Aliolus Say, 1836 of the tribe Brachistini Foerster, 1863 (Hymenoptera, Braconidae, Brachistinae) share a troubled history of more than 100 years, despite an early revision of the Aliolus Nearctic species published by Martin (1956). Mason (1974) proposed a new division based on the type species, and proper nomenclatorial rules. He placed Eubazus and Aliolus as valid genera in the tribe Brachistini of the subfamily Helconinae Foerster, 1863, together with Allodorus Foerster, 1863 and Nealiolus Mason, 1974 (described by him a new genus similar to Aliolus), and placed the genera Calyptus Haliday, 1835 and Brachistes Wesmael, 1835 as subgenera of Eubazus. On basis of molecular research (Belshaw and Quicke 1997) and morphology (van Achterberg 2003) a subfamily status was proposed for the tribe Brachistini. Later, Sharanowski et al. (2011) and Jasso-Martínez et al. (2022) corroborated the subfamily status of the Brachistinae by using more genes and taxa.

Martin (1956) and Mason (1974) treated Aliolus as a valid genus because of the carapace-like metasoma and first tergite movable joined to second tergite and the epipleuron of the second and third tergites sharply delimited from the notum. In Eubazus sensu Mason the epipleuron is not sharply delimited from the notum. It is already obvious from the formulation in the key by Mason (1974) that the difference is gradual in several species. Therefore, van Achterberg (1990) included Aliolus as subgenus in the genus Eubazus “because the degree of separation of the third epipleuron from its notum is highly variable, even within one species” (van Achterberg 1990) and the same applies to the second epipleuron. This observation was mostly based on the Palaearctic species and this variation may be less obvious in Nearctic species. Nevertheless, Papp (1997) and Sharkey (1997) considered Aliolus to be a valid genus, following the classification proposed by Mason (1974). Also, the analysis by Jasso-Martínez et al. (2022) lend support to the treatment of Aliolus as a genus on its own because Aliolus and Eubazus do not form a monophyletic clade Unfortunately, the research is based on one species per genus (but two of Schizoprymnus) and, therefore, too early to change here the rank of Aliolus.

Brachistinae members are koinobiont ovo-larval endoparasitoids of mainly Curculionidae and Mordellidae (van Achterberg 2003; Yu et al. 2016). In addition, some its species were reared from Attelabidae, Bostrichidae, Cerambycidae, Colydidae, Melandryidae, Nitidulidae, Ptinidae (Anobiinae), and Tenebrionidae. Aliolus is no exception; a few known its hosts belong to the Curculionidae (Yu et al. 2016). At least some of the Brachistinae lay their eggs in eggs of the host or very young larvae, develop internally when the host larva is full-grown and have a final ectoparasitoid phase (Haeselbarth 1962; Alauzet 1987; Ghahari et al. 2022; Marigo et al. 2023).

Aliolus is a medium-sized subgenus including 31 valid Holarctic species. So far, 16 species are known from the Nearctic region (Martin 1956; van Achterberg 2003; Yu et al. 2016). During the study of braconids present in the collection of the Ohio State University, Columbus, OH, U.S.A. (OSUC), two new species were discovered: Eubazus (Aliolus) confragosus Yan, sp. nov. and E. (A.) rhyssoeubazus Yan, sp. nov. They are described and illustrated in detail, and an updated key to the Nearctic species of the subgenus Aliolus is provided.

 Material and methods

This work is based on specimens from the Ohio State University Collection of Insects and Spiders. The higher classification at the subfamily level follows Chen and van Achterberg (2019) and Sharanowski et al. (2011). Identification of parasitoids at the genus and subgenus levels was based on the keys provided by van Achterberg (1990) and Sharkey (1997). The key to the Nearctic species of the subgenus Aliolus Say was manually update from Martin (1956). In addition, publicly available photographs of type specimens from the Smithsonian National Museum of Natural History, Washington, D.C., USA (USNM) online collection were examined and compared with the studied material to verify diagnostic characters and the effectiveness of the identification key. The terminology and measurements used follow van Achterberg (1988, 1993). Terminology for sculpture and setation follows Belokobylskij (1998). The following abbreviations are used: POL – postocellar line; OOL – ocular-ocellar line; OD – maximum diameter of lateral ocellus.

All figures and measurements were obtained with Combine ZP and AutoMontage extended-focus software, using a Leica Z16 APOA microscope. Images were post-processed with Adobe Photoshop 2024 Extended.

The type specimens are deposited in the Ohio State University Collection of Insects and Spiders, Columbus, Ohio, U.S.A. (OSUC).

Systematics Animalia Hymenoptera Braconidae 88582F4A-816A-5E0D-A51E-1BEBCDABB948 Eubazus Nees, 1812 Eubazus Nees, 1812: 214; Shenefelt 1970: 230; van Achterberg 1990: 4–5, 2000: 339–340; van Achterberg and Kenis 2000: 427–428, 430; Papp 2005: 163–164. Type species (designated by Viereck 1914): Eubazus pallipes Nees, 1814 [lost]. For synonyms, see van Achterberg and Kenis 2000: 430. Eubadizus Nees, 1834: 233; Shenefelt 1970: 230. Invalid emendation. Type species (indirectly designated by Viereck 1914): Eubazus pallipes Nees, 1814. Eubadizon Nees, 1834: 233; Shenefelt 1970: 229. Invalid emendation. Type species (indirectly designated by Viereck 1914): Eubazus pallipes Nees, 1814. Brachistes Wesmael, 1835: 109; Shenefelt 1970: 229. Type species (designated by Förster 1863): Brachistes ruficoxis Wesmael, 1835 [examined]. Brachystes Rondani, 1876: 59. Invalid emendation. Calyptus Haliday, 1835: 128; Shenefelt 1970: 229; van Achterberg 1990: 5 (as subgenus of Eubazus Nees, 1812). Type species (designated by Haliday 1840): Eubazus macrocephalus Nees, 1814 [lost]. Aliolus Say, 1836: 259; Shenefelt 1970: 269; van Achterberg 1990: 5 (as subgenus of Eubazus Nees, 1812). Type species (designated by Viereck 1914): Bracon (Aliolus) trilobatus Say, 1836 [lost; see van Achterberg (2003)]. Allodorus Foerster, 1862: 242; Shenefelt 1970: 229; van Achterberg 1990: 5 (as subgenus of Eubazus Nees, 1812). Type species (by monotypy): Eubazus semirugosus Nees, 1814 [lost; neotype designated, see van Achterberg and Kenis 2000: 430]. Animalia Hymenoptera Braconidae 9D1F2FBF-8CF4-5279-AFDC-8A5B97B4D574 Aliolus Say, 1836 Aliolus Say, 1836: 259 (as subgenus of Bracon Fabricius, 1804); Shenefelt 1970: 269 (as valid genus in the subfamily TriaspidinaeViereck 1918); van Achterberg 1990: 5; 2003:308 (as subgenus of Eubazus Nees, 1812). Type species

(designated by Viereck, 1914). Bracon trilobatus Say, 1836 (type lost; neotype designated by van Achterberg 2003).

 Diagnosis.

Clypeus transverse; mandible narrowed apically, and distinctly twisted distally; vein CUlb of fore wing present, but sometimes minute; second metasomal suture crenulate and deep or represented by a row of foveae.

 Key to the Nearctic species of the subgenus <italic><tp:taxon-name><tp:taxon-name-part taxon-name-part-type="genus" reg="Aliolus">Aliolus</tp:taxon-name-part></tp:taxon-name></italic> Say

(after Martin (1956); modified to include new species and updated morphological terms).

1 Third metasomal tergite completely smooth and shiny. [Propodeum rounded in lateral view; lower part of lateral region of pronotum without transverse rugae; small species (only the male holotype is known)] E. (A.) evanidus (Martin, 1956)
– Third metasomal tergite at least partly sculptured and rather matt 2
2 Setose part of ovipositor sheath about as long as or longer than three basal metasomal tergites (Fig. 2G) 3
– Setose part of ovipositor sheath shorter than three basal metasomal tergites (Fig. 1A) 11
3 Clypeus with a medial tooth on its ventral margin; [mesopleuron largely sculptured; second suture of metasoma not well developed, being merely a line of impressed foveae] E. (A.) tridentatus (Martin, 1956)
– Clypeus without a medial tooth on its ventral margin (Fig. 2C) 4
4 Postero-lateral angles of mesoscutum strongly produced into knobs, which extend outwards for some distance E. (A.) bicornis (Martin, 1956)
– Postero-lateral angles of mesoscutum not produced into extended knobs, or if well developed, then thin and flange-like 5
5 Lower region of occipital carina strongly tuberculate, with a broad low projection extending laterally above base of mandible E. (A.) bucculentis (Martin, 1956)
– Lower region of occipital carina smoothly rounded and not tuberculate 6
6 Propodeum with strong medio-longitudinal carina extending almost to base of metasomal articulation, distinctly past transverse carina (Fig. 3J); metasoma usually reddish brown 7
– Propodeum with medio-longitudinal carina present, but not extending beyond transverse carina; metasoma usually black 8
7 Notauli very broad and deep, area of their convergence wide and deeply impressed (Fig. 3J) E. (A.) trilobatus (Say, 1836)
– Notauli narrow and area of their convergence not or weakly impressed E. (A.) canadensis (Provancher, 1881)
8 Head rather triangular (anterior view), almost completely smooth and face long; body length about 2.5 mm E. (A.) indeprehensus (Martin, 1956)
– Head rather quadrate (anterior view), punctate or rugose and face short; body length 4.5–5.4 mm 9
9 Rugae of third metasomal tergite more or less converging posteriorly towards its central region, which often consists of a smooth, narrow, central strip; face transversely rugose below antennal sockets; second suture of metasoma consists of row of fine foveae E. (A.) tomoxiae (Rohwer, 1915)
– Rugae or striae of third metasomal tergite more or less straight and covering entire surface; face finely punctate except few rugae or striae upper; second suture of metasoma distinct, and coarsely crenulate (Fig. 2H) 10
10 Mesopleuron largely smooth; notauli posteriorly less sculptured and without a longitudinal median carina E. (A.) fiskei (Rohwer, 1913)
– Mesopleuron coarsely rugose-reticulate (Fig. 2F); notauli posteriorly coarsely rugose-punctate, with a strongly developed median longitudinal carina extending to the middle of the median lobe (Fig. 2E) E. (A.) rhyssoeubazus Yan, sp. nov.
11 Clypeus with a central tooth on its apical margin; [surface of propodeum with a fairly long and strongly developed medio-longitudinal carina; surface of three basal metasomal tergites finely longitudinally rugose-punctate, apex of third metasomal tergite with a narrow impunctate shiny area] E. (A.) denticulatus (Martin, 1956)
– Clypeus without a central tooth on its apical margin 12
12 Notauli rather weakly impressed and scutellar groove shallow; mesosoma and scutellum flat dorsally 13
– Notauli strongly impressed and scutellar groove deep; mesosoma and scutellum at least slightly convex dorsally 14
13 Antenna rather short and broad; mesosoma not definitely flattened ventrally; mesopleuron densely punctate, particularly near precoxal sulcus; scutellum smooth E. (A.) stictopleurus (Martin, 1956)
– Antenna longer and comparatively narrow; mesosoma definitely flat ventrally; mesopleuron sparsely punctate; scutellum finely longitudinally rugose E. (A.) stanleyi (Martin, 1956)
14 Anterior tentorial pits elongate, and large. [Rather finely rugose species] E. (A.) patei (Martin, 1956)
– Anterior tentorial pits circular, and small (Fig. 1C) [Mesopleuron smooth and mainly shiny] 15
15 Postero-lateral carina of lateral lobe of mesoscutum strong and extending as a lateral flange to apex of lateral projection of scutellum between wing bases E. (A.) marginatus (Martin, 1956)
– Postero-lateral carina of lateral lobe of mesoscutum narrow, and not forming a lateral flange to apex of lateral projection of scutellum between wing bases 16
16 Mesopleuron largely irregularly punctate; ventral margin of clypeus broadly obtuse E. (A.) crabilli (Martin, 1956)
– Mesopleuron largely smooth; ventral margin of clypeus evenly curved (Fig. 1C) E. (A.) confragosus Yan, sp. nov.

Note. Eubazus (Aliolus) sayi (Muesebeck & Walkley, 1951) could not be inserted in the key because of uncertainty about its identity (Martin 1956).

Animalia Hymenoptera Braconidae AAA884D4-DBB5-5FB4-BE42-4D0430CC901C Eubazus (Aliolus) confragosus https://zoobank.org/C1BCE364-4498-4DE8-ACDD-DD7C70C1F857 Yan sp. nov. Fig. 1 Material examined.

Holotype: • ♀, 39°36'N, 82°37'W, Ohio, Fairfield Co. OSU Barnebey Center. 9–17.VII.1992, N. F. Johnson, Malaise trap. OSUC 85140 (OSUC). Paratypes: • 2♀♀ + 1♂, topotypic and same date as holotype, OSUC 85144, 85192, 85186 (OSUC); 1 ♀, topotypic but 21–29.VII.1993, OSUC 851505 (OSUC).

 Description.

Female (holotype). Body length (excluding ovipositor sheath) 4.0 mm; length of setose part of ovipositor sheath 1.0 mm; fore wing length 3.4 mm.

Head. Antennomeres 28, third antennomere 0.9 × as long as fourth antennomere, length of third, fourth and penultimate segments 3.0, 3.7 and 1.0 × their width, respectively. Length of maxillary palp 0.8 × height of head. POL: OD: OOL = 11: 20: 8. Occipital carina complete and distinct. Frons slightly concave, laterally sparsely setose, medially almost smooth and rugose-punctate near antennal sockets, with distinct median carina. In dorsal view length of eye 1.5 × length of temple. Vertex and temple sparsely setose, smooth and shiny. Face densely setose and punctate (except for some rugae or striae near antennal sockets), slightly elevated centrally. Malar suture distinct. Length of malar space 0.75 × basal width of mandible. Tentorial pits distinct, distance between pits 1.1 × distance from pit to eye. Clypeus slightly convex and coarsely rugose-punctate, its ventral margin round.

10.3897/jhr.99.188661.figure1 0 B41D3F52-16F9-5F37-BB76-8323AB7D885F

Eubazus (Aliolus) confragosus Yan, sp. nov. A. Habitus, dorsal aspect; B. Head, lateral aspect; C. Head, anterior aspect; D. Head, dorsal aspect; E. Mesosoma, dorsal aspect; F. Mesosoma, lateral aspect; G. Hind leg, lateral aspect; H. Metasoma, dorsal aspect.

https://binary.pensoft.net/fig/1793686

Mesosoma. Length of mesosoma 1.5 × its height. Side of pronotum ventrally rugose-punctate, medially strongly crenulate, dorsally almost smooth. Prepectal carina complete and distinct. Precoxal sulcus smooth, developed as a moderate depression. Notauli complete, crenulate, posteriorly without a median carina. Mesoscutal lobes finely setose and densely punctate. Scutellar sulcus deep, rugose and with one median carina. Scutellum convex, almost smooth. Surface of propodeum anteriorly almost smooth, remainder rugose-reticulate, with a short medio-longitudinal carina and a transverse carina.

Wings. Fore wing, pterostigma 3.0 × as long as wide. Vein 1-R1 1.4 × as long as pterostigma. veins r: SR1: 2-SR = 5: 48: 14. Vein 1-M almost straight. Vein SR1 slightly curved. Vein cu-a postfurcal. Vein m-cu antefurcal. Hind wing, Veins 1-M: 1r-m = 15: 10. Veins M+CU: 1-M = 27: 15. Vein cu-a curved smoothly.

Legs. Hind coxa robust and striate dorsally. Tarsal claw simple. Length of femur, tibia and basitarsus of hind leg 3.1, 7.4 and 4.0 × their width, respectively.

Metasoma. Length of first tergite 0.8 × its posterior width, its dorsal carinae distinct in the basal one-third. Surface of whole carapace coarsely longitudinally rugose-striate. Second suture distinct, straight and coarsely striate. Setose part of ovipositor sheath 0.3 × as long as fore wing, 0.7 × as long as hind tibia and 0.7 × as long as carapace.

Colour. Body black. Palpi yellow. Mandible largely yellow with reddish brown apex. Clypeus and face largely reddish brown (except dark middle part of face). Antennal scape, pedicel, and basal flagellar segments yellowish brown, following antennomeres dark brown. Legs yellowish brown, except brown apical half of femur, hind tibia and hind tarsus brown. Tegulae, pterostigma and ovipositor sheath dark brown. Wing membrane faintly brown. Veins light brown to dark brown.

Variation. Antennomeres 26–28. Length of fore wing 3.1–3.4 mm, of body 3.1–4.0 mm.

Male. Similar to female except antennomeres 27, body length 3.5 cm, fore wing length 2.9 mm.

 Differential diagnosis.

This new species is similar to E. (A.) marginatus (Martin, 1956), but differs in ventral margin of the clypeus evenly curved (clypeus broadly obtuse on its ventral margin in E. (A.) marginatus); notauli posteriorly without wide sculptured area (notauli posteriorly wide and deep, coarsely rugose-punctate. in E. (A.) marginatus); and scutellar sulcus with one median carina (scutellar sulcus with one median and two lateral carinae in E. (A.) marginatus).

 Distribution.

Nearctic region (Ohio, U.S.A.).

 Host.

Unknown.

 Etymology.

Name “confragosus” (Latin for coarse), refers to the coarsely sculptured three basal segments of the metasoma.

 Animalia Hymenoptera Braconidae EC2C7056-2EC8-52BA-BB09-F06B5C78E392 Eubazus (Aliolus) rhyssoeubazus https://zoobank.org/2B293F3F-5128-4BE8-8A9D-CDC4EFDF11EB Yan sp. nov. Fig. 2 Material examined.

Holotype: • ♀, USA, Ohio, Fairfield Co. Barneby Center. 23–30.VII.1992, N. F. Johnson, Malaise trap. OSUC87292 (OSUC). Paratype: • 1♀, USA, Ohio, Fairfield Co. Barneby Center. 1–6.VIII.1992, P. W. Kovarik, T. Philips, FIT [Flight Interception Trap]. OSUC 85317 (OSUC).

 Description.

Female (holotype). Body length (excluding ovipositor sheath) 5.4 mm; length of setose part of ovipositor sheath 2.2 mm; fore wing length 4.2 mm.

Head. Antennomeres 29, third antennomere 0.9 × as long as fourth antennomere, length of third, fourth and penultimate antennomeres 2.8, 2.8 and 1.1 × their width, respectively. Length of maxillary palp 0.8 × height of head. POL: OD: OOL = 7: 4: 17. Occipital carina complete and distinct. Frons moderately concave, reticulate-punctate and setose laterally, medially with some rugae and with a distinct median carina. In dorsal view, length of eye 0.9 × length of temple. Vertex punctate and setose. Temple setose and punctate. Face setose, laterally densely punctate, medially with some transverse rugae. Malar suture present. Length of malar space 1.2 × basal width of mandible. Tentorial pits distinct, distance between pits 0.95 × distance from pit to eye. Clypeus weakly convex, rugose and setose dorsally, ventrally smooth and its ventral margin curved.

10.3897/jhr.99.188661.figure2 0 854FFA07-9E6F-5540-8484-D66571F46594

Eubazus (Aliolus) rhyssoeubazus Yan, sp. nov. A. Habitus, lateral aspect; B. Head, lateral aspect; C. Head, anterior aspect; D. Head, dorsal aspect; E. Mesosoma, dorsal aspect; F. Mesosoma, lateral aspect; G. Hind leg, lateral aspect; H. Metasoma, dorsal aspect.

https://binary.pensoft.net/fig/1793687

Mesosoma. Length of mesosoma 1.3 × its height. Side of pronotum medially widely and coarsely crenulate, posteriorly and ventrally coarsely rugose-punctate and remainder almost smooth. Prepectal carina complete. Mesopleuron coarsely rugose-reticulate and with a median depression. Mesosternal suture distinctly and narrowly crenulate. Notauli complete, crenulate, posteriorly wide and deep, coarsely rugose-punctate, with a strongly developed longitudinal median carina extending to the middle of the median lobe. Mesoscutal lobes sparsely setose, densely and finely punctate. Scutellum convex and punctate. Scutellar sulcus with one carina and rugose-punctate laterally. Surface of propodeum finely and densely punctate anteriorly, remainder coarsely reticulate, its medio-longitudinal carina and anterior transverse carina strongly developed and with a wide medio-anterior area; propodeal tubercles large.

10.3897/jhr.99.188661.figure3 0 E6DC0396-2529-5CD7-8341-F46EC0D9658C

Eubazus (Aliolus) trilobatus (Say), ♀, neotype. A. Wings; B. Head, frontal aspect; C. Habitus, lateral aspect; D. Antenna; E. Detail of mandible, lateral aspect; F. Head, dorsal aspect; G. Hind leg; H. Apex of antenna; I. Inner hind claw; J. Mesosoma, dorsal aspect; K. Metasoma, dorsal aspect (after van Achterberg 2003). Scale bars: 1.0 mm (A, C, D, G, J, K); 0.8 mm (B, F); 0.5 mm (E); 0.2 mm (H, I).

https://binary.pensoft.net/fig/1793688

Wings. Fore wing, pterostigma 3.0 × as long as wide. Vein 1-R1 1.1 × as long as pterostigma. Veins r: SR1: 2-SR = 7: 58: 16. Vein 1-M almost straight. Vein SR1 curved basally. Vein cu-a postfurcal. Vein m-cu moderately antefurcal, almost parallel with vein 1-M. Hind wing, marginal cell slightly narrowed apically. Vein SR straight basally and largely unsclerotized; vein 1r-m long and oblique. Veins 1-M: 1r-m = 17: 16. Veins M+CU: 1-M = 39: 17. Vein cu-a curved moderately.

Legs. Hind coxa densely setiferous and punctate. Tarsal claw simple. Length of femur, tibia and basitarsus of hind leg 3.3, 7.2 and 6.0 × their width, respectively.

Metasoma. Length of first tergite 0.75 × its posterior width, its surface longitudinally and coarsely rugose-striate, its dorsal carinae distinct in the basal 0.4 of tergite. Second and third tergites longitudinally rugose-striate. Second suture distinct, straight and coarsely crenulate. Length of setose part of ovipositor sheath 0.5 × length of fore wing, 1.1 × length of hind tibia and as long as carapace.

Colour. Body mostly black. Palpi yellow. Most of the head (except black vertex and apex of mandible, and yellowish brown base of mandible), antenna, hind femur and hind tarsus reddish brown. Pterostigma and hind tibia dark brown. Tegulae, fore and middle legs and metasomal sternite yellowish brown. Wing fumose with brown to dark brown veins.

Variation. Length of fore wing 4.2–4.4 mm, of body 5.2–5.4 mm.

Male. Unknown.

 Differential diagnosis.

This new species is similar to E. (A.) ubazus (Aliolus) fiskei (Rohwer, 1913), but differs as follows: notauli posteriorly wide and deep, coarsely rugose-punctate, with a strongly developed longitudinal median carina (notauli posteriorly less sculptured and without a longitudinal median carina in E. (A.) fiskei); mesopleuron coarsely rugose-reticulate (mesopleuron largely smooth in E. (A.) fiskei); dorsal carinae of first tergite distinct in the basal 0.4 and distinctly convergent (dorsal carinae strongly developed, subparallel and nearly reaching the apex of the first tergite in E. (A.) fiskei).

 Distribution.

Nearctic region (Ohio, USA).

 Host.

Unknown.

 Etymology.

The name is derived from “rhysso” (Greek for “rugose”) and Eubazus (name of the genus), referring to the genus Eubazus and the rugose mesopleuron and the three basal tergites of the metasoma.

 Acknowledgements

We are grateful to the collectors and curators whose efforts were essential for this study. Special thanks to Lucianna Musetti and Sara Hemly for their support. We also thank Dr Huayan Chen for his help during the course of this study.

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Yu DS, van Achterberg C, Horstmann K (2016) Taxapad 2016. World Ichneumonoidea 2016. Taxonomy, Biology, Morphology and Distribution. Vancouver, Canada. Additional information Conflict of interest

The authors have declared that no competing interests exist.

 Ethical statement

No ethical statement was reported.

 Artificial Intelligence (AI) use

The authors accept full responsibility for the content of the manuscript, including the disclosure of any use of AI.

No AI tools were used in the preparation of this manuscript.

 Funding

This research was supported by the China Scholarship Council (201908330023) and Wencheng County Science and Technology Plan Project (2025NKY12).

 Author contributions

All authors have contributed equally.

 Author ORCIDs

C.-j. Yan https://orcid.org/0000-0001-5723-9635

C. van Achterberg https://orcid.org/0000-0002-6495-4853

N.F. Johnson https://orcid.org/0000-0003-1691-5187

 Data availability

All of the data that support the findings of this study are available in the main text or Supplementary Information.Bularit. Go etiam audam coere nocasto clessedit, vis, P. Catimulin in Etro ut non Itanum dius, quiticenius verestrei inatiaeci tervirm acrum.