﻿The potter wasp genus Allorhynchium from Vietnam, with descriptions of three new species and a new country record (Hymenoptera, Vespidae, Eumeninae)

﻿Abstract Species of the potter wasp genus Allorhynchium van der Vecht (Eumeninae: Odynerini) occurring in Vietnam are presented. Seven species have been recorded from Vietnam. Of them, three species are described as new to science: Allorhynchiumlatum Nguyen, Tran & MT Nguyen, sp. nov., A.moerum Nguyen & AD Nguyen, sp. nov., and A.setosum Nguyen & Engel, sp. nov., and one species, A.argentatum (Fabricius, 1804), is recorded from Vietnam for the first time. An updated key to the Oriental species of the genus is presented.


Introduction
The potter wasp genus Allorhynchium was established by van der Vecht (1963) for a group of Asian eumenines similar to those of the genus Anterhynchium de Saussure, 1863, although the two genera are apparently not closely related (Luo et al. 2022). Allorhynchium can be distinguished from Anterhynchium most notably by the propodeal dorsum raised shelf-like to the same level as the metanotum and the forewing with the prestigma approximately half the length of the pterostigma, as measured along the posterior margin, although some species of the former are now known to share the first character. Recently, several studies have been published on the genus Allorhynchium from India, China, and northeast Asia (Girish Kumar and Sharma 2015;Girish Kumar et al. 2016;Tan et al. 2018;Li et al. 2019;Luo et al. 2020). As a result of this work, a total of 18 species of Allorhynchium have been recorded from the Oriental region. Tan et al. (2018) provided a key to 16 Oriental species at that time. In Vietnam, three species have been recorded in prior studies by Giordani Soika (1986) and Nguyen et al. (2014Nguyen et al. ( , 2018: A. chinense (de Saussure, 1862), A. lugubrinum (Cameron, 1900), and A. quadrimaculatum Gusenleitner, 1997.
Based on extensive material deposited in the IEBR, Hanoi, Vietnam, a taxonomic review of Allorhynchium from Vietnam was undertaken and is presented here. Three new species are described and illustrated, a new country record is added, and an updated key is presented to all Oriental species in the genus.

Materials and methods
Specimens of Allorhynchium were examined from the Insect Ecology Department, Institute of Ecology & Biological Resources (IEBR), Hanoi, Vietnam, and from the private collection of Seiki Yamane, Japan (SYC). Morphological and color characters of mature specimens were observed using pinned and dried specimens under a stereomicroscope Olympus SZ4, and measurements were made with an ocular micrometer. "Body length" indicates the combined lengths of the head, mesosoma, and the first two metasomal segments. Morphological terminology follows that of Carpenter and Cumming (1985) and Yamane (1990). Genitalic terminology follows Kojima (1999) (Fig. 1). Photographic images were made with a Nikon SMZ 800N Digital Stereo Microscope and an attached Sony α6000 digital camera. Images were stacked using Helicon Focus v.7, then grouped into a plate using Adobe Photoshop CS6. The abbreviations F, S, and T (I, II, III, …) refer to numbered flagellomeres, metasomal sterna, and metasomal terga, respectively. Other abbreviations are: NP, National Park; NR, National Reserve; ISD-c, collectors from the Insect Systematic Department (IEBR). Asterisks (*) refer to new locality records for a given species. The names of provinces in Vietnam are arranged in order from north to south and from west to east.  (Fabricius, 1804) Specimens from Vietnam A female, facial view B-E male, facial view F genitalia, inner aspect of paramere with volsella and digitus G genitalia, outer aspect of paramere with volsella and digitus. H aedeagus, ventral view I aedeagus, lateral view. Scale bars: 1 mm.
Remarks. This species is recorded from Vietnam for the first time, but there is a color variation in the male clypeus: entirely black (Fig. 2B), almost black with two narrow transverse yellow strips basally (Fig. 2C), black with a transverse yellow strip basally (Fig. 2D), and black with a thick transverse yellow strip basally plus a large yellow spot medi-apically (Fig. 2E). Male genitalia of the species are described here for the first time.
Male genitalia. As in Fig. 2F-I. Parameral spine lacking setae. Volsella flattened, spatulate, wide on inner aspect, and with setae at top (Fig. 2F, G). Digitus gradually widen from base to two-thirds length, then extended to apex to form two lobes, a black short one with serrated teeth laterally and a transparent lance lobe with dense long setae (Fig. 2F, G). Penis valves long, much longer than basal apodeme (~ 1.36× as long as basal apodeme); in ventral view proximal part strongly produced laterally into oval shape (Fig. 2H); in profile apical part strongly produced into two large lobes (Fig. 2I), upper lobe larger than lower lobe; proximal margin smooth (Fig. 2I Shihtyutou Nantou Hsien, 10.x.1996[10 October 1996. C.C. Luo leg.;1♂, Shihtyutou Nantou Hsien, 8.viii.1996[8 August 1996 [SYC]. Remarks. Although Giordani Soika (1986) recorded this species from Vietnam, we have been unable to examine any specimens from the country. Despite considerable sampling of the genus from throughout Vietnam and the large number of specimens examined, we have not identified any belonging to A. chinense. A new species described herein as A. setosus (vide infra) is quite similar to A. chinense, as discussed under that species, and it is possible that Giordani Soika's (1986) material belongs to that species. As we have not been able to source material from which he based his determinations, we therefore continue to list A. chinense here pending future work. For the moment the status of this species in Vietnam is dubious.
Distribution. China: Sichuan, Yunnan, Hong Kong, Guangdong, Guangxi, Guangzhou, Macao, Jiangxi, Shanghai, Henan, Fujian; Taiwan; ? Vietnam; ? Philippines: Mindanao. Allorhynchium lugubrinum (Cameron, 1900) Fig. 3A Gusenleitner, 1997: 759;Gusenleitner 2011Gusenleitner : 1362Girish Kumar et al. 2016: 34;Tan et al. 2018: 57. margins of terga I and II. Among our material, the latter occurs only in one male, and in this male metasomal sternum II is slightly produced subbasally rather than more or less produced to become tubercules as in other males. Distribution. China: Guangxi, Sichuan, Guizhou, Yunnan; Laos; Vietnam: Cao Bang (*), Tuyen Quang, Yen Bai (*), Bac Kan (*), Vinh Phuc, Bac Giang (*), Phu Tho (*), Hoa Binh (*), Ninh Binh (*), Thanh Hoa (*), Thua Thien Hue (*), Gia Lai (*). ( Diagnosis. This species can be distinguished from other species in the genus by the following combination of characters: head transverse, much wider than high, vertex of female with a small cephalic fovea bearing a tuft of setae medio-dorsally; occipital carina weakly widened laterally; inner compound eye margins strongly convergent ventrally, in facial view 1.3× further apart from each other at vertex than at clypeus; clypeus in frontal view almost as wide as high, apical margin shallowly emarginate medially, forming blunt tooth on each side, distance between teeth > 1/2 width of clypeus between inner compound eye margins; mesoscutum almost as long as wide between tegulae; propodeal dorsum raised shelf-like to same level with metanotum; SVII of male with a raised flat area basally, apical margin of flat area V-shaped. Digitus with two lobes at apex, a dark brown short one and an orange-yellow lance lobe with short hairs; penis valves slightly shorter than the basal apodeme, in profile apical part strongly produced into two lobes, the above lobe round, and larger, the below lobe much smaller and sharper.
Structure. Head in facial view transverse, 1.1× as wide as high (Fig. 4A). Vertex with a small cephalic fovea bearing a tuft of setae medio-dorsally (Fig. 4B). Distance from posterior ocelli to apical margin of vertex 1.8× distance from posterior ocellus to inner compound eye margin (Fig. 4B). Gena narrower than compound eye, ~ 0.8× as wide as compound eye; occipital carina complete, present along entire length of gena, weakly widened laterally (Fig. 4C). Inner compound eye margins strongly convergent ventrally, in anterior view 1.3× further apart from each other at vertex than at clypeus (Fig. 4A). Clypeus in lateral view gradually convex in basal half, then straight to apical margin; in frontal view almost as wide as high (Fig. 4A), with basal margin slightly convex medially and distinctly separated from antennal toruli; apical margin shallowly emarginate medially, forming blunt tooth on each side, distance between teeth > ½ width of clypeus between inner compound eye margins (~ 0.6× width of clypeus between inner compound eye margins). Mandible quadridentate, teeth prominent. Antennal scape ~ 3.8× as long as its maximum width, slightly curved; FI ~ 1.3× longer than wide, FII-III almost as long as wide, FIV-IX wider than long, terminal flagellomere bullet-shaped, ca. as long as its basal width. Mesosoma longer than wide in dorsal view (Fig. 4D). Pronotal carina strongly raised, reaching ventral corner of pronotum. Mesoscutum weakly convex, almost as long as wide between tegulae, without depressed and oblique furrows apically (Fig. 4D). Disc of mesoscutellum convex, in lateral view at same level of mesoscutum ( Fig. 4C), narrowly depressed basally (Fig. 4D). Metanotum weakly convex. Propodeal dorsum raised shelf-like to same level with metanotum; declivity of propodeum with median carina running upward into a narrow and long fovea at a short distance from metanotum, concavity deep and wide. Forewing with third submarginal cell separated from apex of marginal cell by < ½ its length. Metasomal segment I as wide as segment II (Fig. 4F), rounded at base; TI in dorsal view ~ 1.1× as wide as long; TII wider than long, ~ 1.1× as wide as long in dorsal view; SII depressed at base, in lateral view almost straight from base to midlength, then straight to apical margin.
Sculpturing. Clypeus rugose, interspaces between punctures with minute punctures, each puncture bearing a medium-long bristle. Frons densely covered with coarse flat-bottom punctures, interspaces between punctures narrow and raised to form reticulation. Vertex with coarse punctures, punctures equal in size, interspaces with sparse minute punctures; gena with punctures similar to those on vertex from midlength to vertex, punctures smaller and less coarse in basal half (  flat-bottomed punctures, punctures equal in size, smaller than those on pronotum, interspaces between punctures with sparse minute punctures, smooth, larger than puncture diameter centrally, punctures at margins stronger and larger than those centrally; mesoscutellum with punctures similar to those on mesoscutum, punctures on metanotum denser than those on mesoscutellum, interspaces between punctures narrow and raised to form reticulation. Mesepisternum with flat-bottomed punctures, punctures coarser to those on pronotum posterodorsally, smooth anteroventrally; border between posterodorsal and anteroventral parts distinct, without epicnemial carina. Dorsal part of metapleuron largely smooth and with several short and weak striae, ventral part with sparse and shallow punctures. Propodeum with very coarse and dense punctures dorsally, punctures much shallower and weaker to form weak transverse striae laterally, interspaces between punctures strongly raised to form reticulation, dorso-lateral margin of propodeum somewhat rounded; posterior surface rugose basally and with some short oblique striations near median carina apically. Tegula with minute punctures. Metasomal TI covered with sparse and strong punctures dorsally, fine punctures dorso-anteriorly, distance between punctures greater than puncture diameter, interspaces with minute punctures; punctures on TII smaller and shallower than those on TI, punctures on TIII-V and SII denser than those on TII; TVI and SVI with minute punctures. Color. Body almost black except two short yellow bands along inner orbits near clypeus and brown valvulae. Wing infuscate, veins dark brown (Fig. 8D).
Pubescence. Body with medium-length silver setae. Male (Fig. 5). Body length 11.9-12.3 mm; forewing length 11.4-11.7 mm. Structure. As in female but differing as follows: head transverse, much wider than high, 1.2× as wide as high in facial view (Fig. 5A); vertex without cephalic foveae; distance from posterior ocelli to apical margin of vertex ~ 2.2× distance from posterior ocelli to inner compound eye margin; inner compound eye margins strongly convergent ventrally, in facial view 1.2× as further apart from each other at vertex as at clypeus; clypeus in frontal view as wide as long, apical margin slightly emarginate medially, forming blunt tooth on each side (Fig. 5A), width of emargination much greater than one-third of clypeal width between inner compound eye margins (0.4× width of clypeus between inner compound eye margins); mandible with short teeth. Antennal scape ~ 4.45× as long as wide, FI ~ 1.5× as long as wide, FII-IV longer than wide, FV-VII as wide as long, FVIII wider than long, FIX slightly longer than wide, FX much smaller than FIX, terminal flagellomere elongate, slightly curved, ~ 3× as long as its basal width (Fig. 5B). Metasomal SVII with a raised flat area basally, apical margin of flat area V-shaped (Fig. 5C).
Sculpturing. Body surface sculptured as in female; clypeus with sparse and small punctures, distance between punctures greater than puncture diameter and with dense minute punctures.
Pubescence. As in female except clypeus covered with dense, medium-long, silver setae laterally.
Color. Similar to female. Genitalia. As in Fig. 5E-H. Parameral spine lacking hairs. Volsella flattened, spatulate, wide on inner aspect, and without hairs at top (Fig. 5E, F). Digitus gradually widened from base to two-thirds length, then extended apically to form two lobes, a dark brown short one and an orange-yellow lance lobe with short hairs (Fig. 5E, F). Penis valves long, ~ 1.7× as long as basal apodeme, in ventral view proximal part produced laterally into an oval shape (Fig. 5G); in profile apical part strongly produced into two lobes (Fig. 5H), upper lobe round and larger, lower lobe much smaller and sharper; proximal margin smooth (Fig. 5H).
Distribution. Central Vietnam. Etymology. The specific epithet is from the Latin participle lātus (meaning broad or wide), and refers to the wide apical emargination of the clypeus.
Remarks. The new species is similar to A. argentatum in that all have the occipital carina slightly widened laterally, the propodeal dorsum raised shelf-like to the same level of the metanotum, the posterior surface of the propodeum rugose basally and with some short oblique striations near the median carina apically, TI finely punctate anteriorly, and TII with small and sparse punctures. However, it differs from A. argentatum in the following characters: head transverse, apical margin of clypeus with wide emargination, > ½ and > 1/3 width of clypeus between inner compound eye margins in female and male, respectively (~ 1/3 width of clypeus between inner compound eye margins in both female and male in A. argentatum); mandible of male with short teeth (mandible of male with prominent teeth in A. argentatum); SVII of male with apical margin of raised flat area V-shaped (SVII with apical margin of raised flat area wide in A. argentatum); penis valves short, slightly shorter than the basal apodeme (penis valves long, much longer than the basal apodeme in and A. argentatum); proximal part of aedeagus in profile with two lobes, the below lobe small and sharp (proximal part of aedeagus in profile with two lobes, the below lobe much larger and blunter in A. argentatum). Diagnosis. This species can be distinguished from other species in the genus by the following character combination: head of female in facial view transverse, 1.2× as wide as high; vertex of female produced behind ocelli, with small cephalic foveae situated next to each other and each bearing a tuft of setae; clypeus in frontal view slightly wider than high, apical margin shallowly emarginate medially, forming blunt tooth on each side, distance between teeth slightly > 1/3 width of clypeus between inner compound eye margins; mesoscutum slightly shorter than wide; propodeal dorsum raised shelf-like to same level with metanotum, concavity deep and wide, margined by a crest, posterior surface clearly separated from dorsal and lateral surfaces by a curved rim, rim strongly produced behind metanotum to form serrate teeth; SVII of male with raised flat area basally, apical margin of raised flat area wide; volsella with long setae at the top.
Structure. Head in anterior view subcircular, 1.1 × as wide as high (Fig. 6A). Vertex with small cephalic foveae situated next to each other, each bearing a tuft of setae (Fig. 6B). Distance from posterior ocelli to apical margin of vertex 2.3× distance from posterior ocellus to inner compound eye margin (Fig. 6B). Gena narrower than compound eye, ~ 0.86× as wide as compound eye; occipital carina complete, present along entire length of gena, widened laterally. Inner compound eye margins strongly convergent ventrally, in facial view 1.2× further apart from each other at vertex than at clypeus. Clypeus in lateral view prominently convex in basal half, then straight to apical margin; in frontal view slightly wider than high, ~ 1.04× as wide as high (Fig. 6A), with basal margin slightly convex medially and distinctly separated from antennal toruli; apical margin shallowly emarginate medially, forming blunt tooth on each side, distance between teeth slightly > 1/3 width of clypeus between inner compound eye margins (~ 0.4× width of clypeus between inner compound eye margins). Mandible quadridentate. Antennal scape ~ 4.3× as long as its maximum width, slightly curved; FI ~ 1.4× longer than wide, FII slightly longer than wide, FIII-IX wider than long, terminal flagellomere bullet-shaped, ca. as long as its basal width. Mesosoma longer than wide in dorsal view (Fig. 6C). Pronotal carina slightly raised, reaching ventral corner of pronotum. Mesoscutum weakly convex, slightly shorter than wide, 0.95× as long as wide between tegulae, with two depressed and oblique furrows running from apical margin to one-fifth length of mesoscutum (Fig. 6C). Disc of mesoscutellum almost flat, in lateral view at same level of mesoscutum, depressed basally (Fig. 6C). Metanotum weakly convex. Declivity of propodeum with median carina running upward into a deep, oval, fovea at a short distance from metanotum, propodeal dorsum raised shelf-like to same level with metanotum, concavity deep and wide, margined by a crest, posterior surface clearly separated from dorsal and lateral surfaces by a curved rim, rim strongly produced behind metanotum to form serrate teeth (Fig. 6E). Forewing with third submarginal cell separated from apex of marginal cell by < ½ its length. Metasomal segment I (Fig. 6F) as wide as segment II, rounded at base; TI in dorsal view ~ 1.7× as wide as long; TII longer than wide, ~ 1.1× as long as wide in dorsal view; SII depressed at base, in lateral view almost straight from base to midlength, then straight to apical margin.
Sculpturing. Clypeus with strong punctures, punctures on flattened part larger and shallower, interspaces between punctures with minute punctures, each puncture bearing a very short bristle. Frons densely covered with coarse flat-bottom punctures, interspaces between punctures with sparse minute punctures and raised to form reticulation. Vertex with punctures slightly smaller than those on frons, interspaces larger than on frons; gena from midlength to vertex with punctures similar to those on vertex, and with smaller and weaker punctures on apical half (Fig. 6D); occipital carina weakly widened laterally (Fig. 6D). Pronotum with punctures similar to those on vertex. Mesoscutum densely and coarsely covered with flat-bottomed punctures, punctures equal in size, smaller than those on pronotum, interspaces between punctures raised to form reticulation; mesoscutellum with coarse, sparser, and smaller punctures than those on mesoscutum, several small impunctate areas between coarse punctures (i.e., lacking minute punctures), punctures on metanotum similar to those on mesoscutellum but denser. Mesepisternum with flat-bottomed punctures, punctures coarser to those on pronotum posterodorsally, smooth anteroventrally; border between posterodorsal and anteroventral parts distinct, without epicnemial carina. Dorsal part of metapleuron with several strong striae, ventral part with small, sparse, shallow punctures. Propodeum with very coarse and dense punctures on dorsal part, interspaces between punctures strongly raised to form reticulation, lateral part with transverse striae; posterior surface shiny and largely smooth, with some short oblique striations near median carina apically. Tegula with minute punctures. Metasomal TI with sparse strong punctures, distance between punctures greater than puncture diameter, interspaces with minute punctures; punctures on TII larger and deeper than those on TI, punctures on TIII-V and SII denser than those on TII; TVI and SVI with minute punctures.
Color. Body almost black except two yellow bands along compound eyes near clypeus and brown valvulae. Wing strongly infuscate, with purple highlights, veins dark brown (Fig. 7D).
Pubescence. Body with medium-length silver setae. Male (Fig. 7). Body length 11.0-11.7 mm; fore wing length 9.8-11.5 mm. Structure. As in female but differing as follows: head slightly wider than high, 1.0× as wide as high in anterior view (Fig. 7A); vertex without cephalic foveae; distance from posterior ocelli to apical margin of vertex ~ 2.15× distance from posterior ocelli to inner compound eye margin; inner compound eye margins strongly convergent ventrally, in facial view 1.3× further apart from each other at vertex than at clypeus; clypeus in frontal view almost as wide as long, apical margin deeply emarginate medially, upside down V-shaped, forming sharp pointed tooth on each side (Fig. 7A), width of emargination ~ 1/3 of clypeal width between inner compound eye margins; mandible quadridentate (with four teeth). Antennal scape ~ 3.5× as long as wide, FI ~ 1.6× as long as wide, FII-III longer than wide, FIV-V as wide as long, FVI-VIII wider than long, FX much smaller than FIX, terminal flagellomere elongate, slightly curved, ~ 2× as long as its basal width (Fig. 7A). SVII with a raised flat area basally (Fig. 7B).
Sculpturing. Body surface sculptured as in female; clypeus with coarse but without flat-bottom punctures, distance between punctures greater than in female (Fig. 7A).
Pubescence. As in female except clypeus with dense, long, silver setae. Color. Similar to female; clypeus usually black but in some specimens, clypeus with two yellow spots subbasally or with one yellow spot medio-apically and a transverse strip basally.
Genitalia. As in Fig. 7 (E-H). Parameral spine lacking hairs. Volsella flattened, spatulate, wide on inner aspect, and with hairs at top (Fig. 7E, F). Digitus gradually widened from base to two-thirds length, then extended apically to form two lobes, a black short one and a transparent lance lobe with dense long hairs (Fig. 7E, F). Penis valves long, much longer than basal apodeme (~ 2.1× as long as basal apodeme); in ventral view proximal part strongly produced laterally into oval shape (Fig. 7G); in profile apical part strongly produced into two large lobes (Fig. 7H), upper lobe larger than lower lobe; proximal margin smooth (Fig. 7H).
Distribution. North and central Vietnam.
Etymology. The specific epithet is from Old Latin moerus (= Latin mūrus; meaning a wall, a rim, or a dam), and refers to the rim separating the dorsal and posterior surfaces of the propodeum.
Remarks. This new species is similar to A. chinense in having the occipital carina being widened laterally; the posterior surface of the propodeum shiny and largely smooth; the propodeal dorsum raised shelf-like to the same level of the metanotum, a deep and wide concavity margined by a crest, and the posterior surface clearly separated from the dorsal and lateral surfaces by a curved rim, the rim produced behind the metanotum to form serrate teeth; SVII of the male with a raised flat area basally; and the forewing strongly infuscate, with purple highlights. However, it differs from the latter by the following characters: body with less coarse punctures (body with coarse punctures in A. chinense); pronotum in dorsal view slightly swollen laterally (pronotum in dorsal view strongly swollen laterally); in male, volsella with long setae at the top (volsella without setae at the top in A. chinense).  19°47'24.5"N, 104°59'46.5"E, alt. 729 m, 25.iv.201619°47'24.5"N, 104°59'46.5"E, alt. 729 m, 25.iv. [25 April 2016 Diagnosis. This species can be distinguished from congeners by the following character combination: vertex of female with a small cephalic fovea bearing a tuft of setae medio-dorsally; occipital carina weakly widen laterally; inner compound eye margins strongly convergent ventrally, in anterior view 1.2× as further apart from each other at vertex as at clypeus; clypeus with apical flattened half well defined, in facial view wider than high; mesoscutum almost as long as wide between tegulae; propodeal dorsum raised shelf-like to same level with metanotum, concavity shallow and narrow; SVII of male with a raised flat area basally, apical margin of raised flat area pointed medially. In male genitalia, digitus extend to apex to form two lobes, a short black lobe smooth laterally, and a transparent wide lobe with dense long setae and several short and thicker setae; penis valves with several setae at basal one-third; proximal part of penis valves in profile with an apical part strongly produced into two large lobes.
Structure. Head in facial view subcircular, 1.1× as wide as high (Fig. 8A). Vertex with a small cephalic fovea bearing a tuft of setae medio-dorsally (Fig. 8B). Distance from posterior ocelli to apical margin of vertex 1.8× distance from posterior ocellus to inner compound eye margin (Fig. 8B). Gena narrower than compound eye, ~ 0.8× as wide as compound eye; occipital carina complete, present along entire length of gena, weakly widened laterally. Inner compound eye margins strongly convergent ventrally, in anterior view 1.2× further apart from each other at vertex than at clypeus. Clypeus with apical flattened half well defined, in lateral view prominently convex in basal half, then straight to apical margin, in anterior view wider than high, ~ 1.1× as wide as high (Fig. 8A), with basal margin slightly concave medially and distinctly separated from antennal toruli; apical margin shallowly emarginate medially, forming blunt tooth on each lateral side, distance between teeth slightly > 1/3 width of clypeus between inner compound eye margins (~ 0.4× width of clypeus between inner compound eye margins). Mandible quadridentate (with four teeth), teeth prominent. Antennal scape ~ 4.1× as long as its maximum width, slightly curved; FI ~ 1.4× longer than wide, FII slightly longer than wide, FIII-IX wider than long, terminal flagellomere bullet-shaped, ca. as long as its basal width. Mesosoma longer than wide in dorsal view (Fig. 8C). Pronotal carina raised, reaching ventral corner of pronotum. Mesoscutum weakly convex, almost as long as wide between tegulae, without depressed and oblique furrows apically (Fig. 8E). Disc of mesoscutellum slightly convex, in lateral view at same level of mesoscutum, narrowly depressed basally (Fig. 8C). Metanotum weakly convex. Propodeal dorsum raised shelf-like to same level with metanotum; declivity of propodeum with median carina running upward into a narrow and long fovea at short distance from metanotum, concavity shallow and narrow. Forewing with third submarginal cell separated from apex of marginal cell by < ½ its length (Fig.  8D). Metasomal segment I as wide as segment II (Fig. 8F), rounded at base; TI in dorsal view ~ 1.6× as wide as long; TII wider than long, ~ 1.2× as wide as long in dorsal view; SII depressed at base, in lateral view almost straight from base to midlength, then straight to apical margin.
Sculpturing. Clypeus rugose, basal and lateral parts with strong punctures, interspaces between punctures with minute punctures, each puncture bearing a medium-long bristle. Frons densely covered with coarse flat-bottom punctures, interspaces between punctures narrow and raised to form reticulation. Vertex with strong and deep punctures, punctures equal in size, interspaces with sparse minute punctures; gena from midlength to vertex with punctures similar to those on vertex, and with smaller and weaker punctures on apical half (Fig.  8D); occipital carina weakly widened laterally (Fig. 8D). Pronotum with punctures similar to those on vertex. Mesoscutum covered with flat-bottomed punctures, punctures equal in size, smaller than those on pronotum, interspaces between punctures with sparse minute punctures, smooth, larger than puncture diameters centrally, punctures at margins stronger and larger than those centrally; mesoscutellum with punctures similar to those on mesoscutum, punctures on metanotum denser than those on mesoscutellum, interspaces between punctures narrow and raised to form reticulation. Mesepisternum with flat-bottomed punctures, punctures coarser than those on pronotum posterodorsally, smooth anteroventrally; border between posterodorsal and anteroventral parts distinct, without epicnemial carina. Dorsal part of metapleuron with several strong striae, ventral portion of metapleuron with dense and shallow punctures. Propodeum with dorsolateral margin of propodeum somewhat rounded, punctures on dorsolateral area coarse and irregularly rugose, interspaces carinate, sometimes Figure 9. Allorhynchium setosum Nguyen & Engel, sp. nov., male paratype, female holotype A male, facial view B male, right antenna C male, metasomal sternum VII D female, lateral habitus E male genitalia, inner aspect of paramere with volsella and digitus F male genitalia, outer aspect of paramere with volsella and digitus G aedeagus, ventral view H aedeagus, lateral view. Scale bars: 1 mm.
with teeth-like structures behind metanotum, posterior surface rugose basally and with some short oblique striations near median carina apically. Tegula covered with minute punctures. Metasomal TI covered with sparse strong punctures dorsally, and fine punctures dorso-anteriorly, distance between punctures greater than puncture diameter, with minute punctures in interspaces; punctures on TII smaller and shallower than those on TI, punctures on TIII-V and SII denser than those on TII; TVI and SVI with minute punctures.
Color. Body almost black except two short yellow bands along inner orbits near clypeus and brown valvulae. Wing infuscate, veins dark brown (Fig. 9D).
Pubescence. Body with medium-length silver setae. Male (Fig. 9). Body length 10.4-10.6 mm; fore wing length 9.9-10.1 mm. Structure. As in female but differing as follows: head wider than high, 1.1× as wide as high in facial view (Fig. 9A); vertex without cephalic foveae; distance from posterior ocelli to apical margin of vertex ~ 2.2× distance from posterior ocelli to inner compound eye margin; inner compound eye margins strongly convergent ventrally, in anterior view 1.3× further apart from each other at vertex than at clypeus; clypeus in anterior view slightly wider than high, apical margin deeply emarginate medially, forming sharply pointed tooth on each side (Fig. 9A), width of emargination greater than one-third of clypeal width between inner compound eye margins (0.4× width of clypeus between inner compound eye margins); mandible with short and wide teeth. Antennal scape ~ 3.6× as long as wide, FI ~ 1.6× as long as wide, FII longer than wide, FIII and FIX as wide as long, FIV-VIII wider than long, FX much smaller than FIX, terminal flagellomere elongate, slightly curved, ~ 3× as long as its basal width (Fig. 9B). Metasomal SVII with a raised flat area basally, apical margin of flat area pointed medially (Fig. 9C).
Sculpturing. Body surface sculptured as in female; clypeus with sparse and small punctures, distance between punctures greater than puncture diameter and with dense minute punctures.
Pubescence. As in female except clypeus covered with dense, medium-long, silver setae.
Color. Similar to female. Genitalia. As in Fig. 9E-H. Parameral spine lacking setae. Volsella flattened, spatulate, wide on inner aspect, and with long setae at top (Fig. 9E, F). Digitus gradually widened from base to two-thirds length, then extended apically to form two lobes, a dark-brown short one smooth laterally, and a transparent wide lobe with dense long setae and several additional short and thicker setae (Fig. 9E, F). Penis valves long, much longer than basal apodeme (~ 2× as long as basal apodeme), with several setae in basal third; in ventral view proximal part strongly produced laterally into an oval shape (Fig. 9G); in profile apical part strongly produced into two large lobes (Fig. 9H), upper lobe larger than lower lobe; proximal margin smooth (Fig. 9H).
Distribution. North, Central, and Highland of Vietnam. Etymology. The specific epithet is the Latin adjective sētōsus (meaning shaggy), and refers to the setae on the basal third of the penis valves and apex of the digitus (Fig. 9E-H).
Remarks. This new species is closely similar to A. argentatum in having the occipital carina slightly widened laterally, the propodeal dorsum raised shelflike to the same level with the metanotum, the clypeus of the female with a rather deep and wide emargination apically, and the clypeus of the male densely covered with silvery setae. However, it differs from the latter by the following traits: mesoscutum as long as wide between tegulae (mesoscutum wider than long, 1.2× wider than long in A. argentatum), mandible of the male with short and wide teeth (mandible of the male with prominent long teeth in A. argentatum), SVII of the male with the apical margin of the raised flat area pointed medially (SVII with apical margin of raised flat area wide medially in A. argentatum), apex of digitus with two lobes, the short one blunter, the setose transparent lobe much wider and with several short and thick setae (apex of digitus with two lobes, the short one sharper, the setose transparent lance shape and without setae in A. argentatum), penis valves with several setae at basal onethirds (penis valves without setae at base in A. argentatum).
This new species is also similar to A. latum sp. nov. in having the occipital carina slightly widened laterally, the propodeal dorsum raised shelf-like to the same level with the metanotum, mesoscutum as long as wide between tegulae. But it differs from the latter by the following characters: clypeus wider than high (clypeus as wide as high in A. latum), distance between teeth of clypeus < ½ width of clypeus between inner compound eye margins (distance between teeth of clypeus > ½ width of clypeus between inner compound eye margins in A. latum), penis valves in profile with lower lobe of apical margin round (penis valves in profile with lower lobe of apical margin produced to a narrow and sharp lobe in A. latum).

Key to oriental species of Allorhynchium
A key is provided here to the 21 recognized Oriental species in the genus Allorhynchium. Some species with the propodeum not level with the metanotum, such as A. anomalum, A. diffinis, A. lugubrinum, A. quadrimaculatum, A. menglianense, and A. radiatum, are tentatively treated under the genus Allorhynchium. Further study is needed along with a revision and new key to Oriental eumenine genera so that Allorhynchium can be newly redefined and identified properly.