Archancistrocerus diffinis Tan & Achterberg & He & Carpenter, 2018

Tan, Jiang-Li, Achterberg, Cornelis Van, He, Yi-Fei & Carpenter, James M., 2018, Northeast Asian Allorhynchium van der Vecht (Hymenoptera: Vespidae), with a key to Oriental species, Zootaxa 4434 (1), pp. 49-64 : 51-54

Key to Oriental species of Allorhynchium van der Vecht

1 T1 with distinct transverse rim medio-laterally ( Figs 29, 30 ); clypeus vermiculate-reticulate ( Fig. 31 ); tegula, clypeus of ♀, inter-antennal area, pronotum anteriorly, metanotum, mesepisternum dorsally and propodeum laterally, yellow ( Figs 1, 2 ); S7 of ♂ with 3 small teeth basally ( Fig. 44 in Giordani Soika, 1986b); [T2 densely punctate or reticulate basally]; China (Sichuan, Fujian)............................................................ A. diffinis (Giordani Soika, 1986) comb. n. - T1 more or less evenly rounded medio-laterally ( Figs 42, 43 , 52 ), but intermediate in some species, e.g. A. quadrimaculatum ( Fig. 59 ); clypeus punctate ( Fig. 62 ), sometimes reticulate rugose-punctate ( Fig. 53 ); tegula black or reddish brown; clypeus of ♀, inter-antennal area, pronotum anteriorly, metanotum, mesepisternum dorsally and propodeum laterally, black ( Fig. 4 ); S7 of ♂ either with 2 small teeth basally ( Fig. 64 ) or with only a shiny and flat elevation ( Figs 16 , 44 )....................... 2

2 Occipital carina wide laterally ( Fig. 13 ); medio-dorsally propodeum with serrate crest protruding above medial depression ( Fig. 19 ); propodeum deeply concave and strongly shiny medially ( Figs 15 , 23 ); clypeus of ♂ entirely black; smooth area on S7 of ♂ distinctly protruding postero-ventrally ( Fig. 16 ); China (Sichuan, Taiwan; Guangzhou, Macao, Jiangxi (NWUX), Shanghai, *Henan (NWUX), *Fujian (RMNH)), Vietnam,?Philippines (fide Marco Selis: the presence of this species in the Philippines is quite doubtful and could be a misidentification of A. violaceipenne or an undescribed species common in many islands of the archipelago)...................................................... A. chinense (de Saussure, 1862)

- Occipital carina medium-sized laterally ( Figs 41 , 50 , 57 ); medio-dorsally propodeum not protruding above medial depression ( Figs 47 , 59 ), at most with a serrate margin ( Fig. 7 ); propodeum shallowly to moderately concave and with satin sheen medially ( Figs 7 , 43 , 55 , 59 ); clypeus of ♂ often partly ivory or yellowish; smooth area on S7 of ♂ often slightly protruding postero-ventrally ( Fig. 8 )................................................................................ 3

3 Clypeus with narrow V-shaped or circular medio-apical emargination and wide apico-lateral lobes ( Fig. 66 ); clypeus of ♂ with pale yellowish longitudinal band and remainder black; veins and membrane of basal half of fore wing yellowish; vertex of ♀ with tuft of setae in small depression (“cephalic fovea’) medio-dorsally; [T1 and T2 black apically]; Indonesia (Java).................................................................................. A. concolor van der Vecht, 1963

- Clypeus broadly emarginated and with apico-lateral lobes or teeth narrow ( Figs 67–69 ) or truncate ( Figs 70, 71 ) apically; clypeus of ♂ variable, often with pale yellowish transverse band basally; colour of veins and membrane of basal half of fore wing variable; vertex of ♀ often without setose cephalic fovea (but present in A. violaceipenne , A. obscurum , A. vollenhoveni and A. cariniventre ).................................................................................... 4

4 Lateral areas of pronotum in dorsal view flattened and with distinct protuberance laterally; T1 rather angulate in lateral view; vertex of ♀ with tuft of setae in small cephalic fovea medio-dorsally............................................ 5

- Lateral areas of pronotum in dorsal view convex and at most slightly protruding laterally; T1 often rounded in lateral view; vertex of ♀ often without tuft of setae in small cephalic fovea medio-dorsally (but present in A. obscurum and A. violaceipenne );.............................................................................................. 6

5 Veins and membrane of basal 0.6 of fore wing yellowish; clypeus truncate apically or nearly so ( Figs 70, 71 ); [S2 of ♂ (if width of pronotum 4–5 mm) with pair of truncate protuberances, but size varies and in small specimens (width of pronotum 3– 4 mm) entirely lacking]; Indonesia (Sunda area); [syn.: Rhynchium mamillatum von Schulthess, 1931 ]........................................................................................... A. vollenhoveni (de Saussure, 1862)

- Veins and membrane of fore wing entirely fuscous with metallic reflections; clypeal emargination medio-dorsally curved because of small lobe ( Fig. 2 in Gusenleitner, 1998); Philippines................... A. cariniventre Giordani Soika, 1986

6 Dorsal half of propodeal depression largely densely yellowish pubescent; clypeus subtruncate apically; T1 with reddish or dark brown apical band; wings largely subhyaline but apically dark brown; head and mesosoma coarsely punctate; [vertex of ♀ with tuft of setae medio-dorsally]; Indonesia ( Sunda area ) ; Malaysia (N. Borneo).................. A. obscurum ( Smith, 1858)

- Dorsal half of propodeal depression largely glabrous; clypeus protruding latero-apically ( Figs 45 , 62 , 69 ); T1 black or with pair of yellow patches apically; wings usually largely dark brown with bluish iridescence; head and mesosoma usually moderately punctate............................................................................................. 7

7 Clypeus of both sexes squarely and usually rather deeply emarginate, resulting in two widely separated teeth or narrow lobes apico-ventrally ( Figs 67–69 ); width of clypeal emargination 0.5–0.7 × clypeal width at same level; clypeus of ♂ entirely black; S7 of ♂ with flat and apically nearly truncate smooth protruding area; [T1 rather angulate in lateral view]............... 8

- Clypeus of both sexes circularly or elliptically emarginated apically, resulting in pair of less separated lobes or teeth apico-ventrally ( Figs 9 , 45 , 62 ); width of clypeal emargination 0.2–0.5 × clypeal width at same level; clypeus colour and shape of S7 of ♂ variable........................................................................................... 9

8 Clypeus shallowly emarginate medio-apically; vertex with narrow transverse and slightly raised impunctate area behind posterior ocelli; metasoma relatively coarsely punctate; Philippines.............. A. quadrituberculatum (von Schulthess, 1913)

- Clypeus distinctly emarginate medio-apically, straight or nearly so (( Fig. 3 e, f in van der Vecht 1963, Figs 67–69 ); vertex without transverse and slightly raised impunctate area medio-dorsally; metasoma moderately punctate; [hind wing hyaline in the basal half; punctures on dorsal faces of propodeum relatively sparse; Vietnam, Indonesia (Sunda area), Philippines; [syn.: Odynerus aurivillianus von Schulthess, 1913 ]....................................... A. snelleni (de Saussure, 1862)

Note. For a key to the three subspecies i.e. A. s. snelleni (de Saussure) , A. s. javanum (de Saussure) and A. s. imitator van der Vecht, see van der Vecht (1963)

9 Scapus and pedicellus, all femora and tibiae, and two large spots on propodeum reddish brown; subbasal area of S7 of ♂ flat; [apex of T1 and T2 with yellow or dull reddish yellow band (sometimes medially interrupted); clypeus of ♂ largely black, at most with two transverse yellowish spots basally]; Indonesia (Sunda area), Timor, Sumba... A. tigrinum van der Vecht, 1963

Note. For the two subspecies i.e. T. t. tigrinum van der Vecht and T. t. atripenne Giordani Soika, see Giordani Soika (1986a, 1991)

- Scapus and pedicellus, all femora and tibiae, and propodeum black; subbasal area of S7 of ♂ partly elevated............ 10

10 Posterior half of T1 and basal half of T2 of ♀ at most sparsely punctulate ( Fig. 52 ), of ♂ superficially punctate ( Figs 42 , 4 3 ).................................................................................................... 11

- Posterior half of T1 and basal half of T2 of ♀ with medium-sized and distinctly impressed punctures ( Fig. 59 )................................................................................................................ 12

11 Medial length of clypeus 0.9 × its maximum width ( Fig. 45 ); depth of emargination 0.2–0.3 × width of clypeus at level of emargination ( Fig. 45 ); Pakistan, India, Sri Lanka, Maldives, Nepal, Myanmar, Malaysia (N. Borneo), Indonesia ( Moluccas), China ( Taiwan, * Tibet (NWUX), * Yunnan (NWUX)); [syn.: Rhynchium maldivense Cameron, 1901 ]............................................................................................. A. metallicum (de Saussure, 1852)

-... Medial length of clypeus 1.1 × its maximum width; depth of emargination 0.1 × width of clypeus at level of emargination; Philippines............................................................... A. violaceipenne Gusenleitner, 2003

12 Clypeus of ♂ with a tuberculate projection near its apical half ( Fig. 3 in Girish Kumar et al., 2016); basally clypeus of ♂ with a narrow transverse yellowish white band; India (Kerala); [♀ unknown]... A. tuberculatum Girish Kumar & Carpenter, 2016

- Clypeus of ♂ without any projection ( Figs 9 , 62 ); clypeus of ♂ without more or less separate basal pale band ( Figs 9 , 62 ).. 13

13 Antero-dorsal surface of propodeum almost at same level as dorsal surface of metanotum and scutellum ( Figs 6, 7 ); protruding subbasal area of S7 of ♂ subparallel-sided and wide medially ( Fig. 8 ); [gena densely silvery setose ( Fig. 6 ); clypeus of ♀ with rather deep and wide emargination apically ( Fig. 8 ); clypeus of ♂ densely silvery setose ( Fig. 9 ) and more or less with a yel- lowish pattern]; Pakistan, India, Nepal, Myanmar, Thailand, Laos, Malaysia, Singapore, Indonesia (Sunda area & Sulawesi), Philippines; [syn.: Rhynchium clypeatum Cameron, 1900 ]............................ A. argentatum ( Fabricius, 1804) - Antero-dorsal surface of propodeum well below dorsal surface of metanotum and scutellum ( Figs 57–59 ); protruding subbasal area of S7 of ♂ either wide and medially constricted, with pair of flat lobe-shaped protuberances ( Fig. 12 in Girish Kumar & Sharma 2015) or with pair of triangular teeth ( Fig. 64 )....................................................... 14

14 T2 (as T1) entirely black apically; clypeus of ♂ entirely black; protruding smooth subbasal area of S7 of ♂ wide and medially constricted ( Fig. 12 in Girish Kumar et al. 2016); wings moderately infuscate ( Fig. 7 l.c .); T1 finely punctate anteriorly; [junction of anterior and dorsal faces of T1 rather angulate]; India (Kerala)................. A. anomalum Giordani Soika, 1992

- T2 with pair of yellow patches latero-apically ( Fig. 50 ), and patch of T1 reduced or distinct; clypeus of ♂ yellow but laterally and its narrow ventral margin black ( Figs 61, 62 ); S7 of ♂ with pair of triangular teeth ( Fig. 64 ) or pair of flat lobe-shaped protuberances ( Fig. 12 in Girish Kumar & Sharma 2015); wings entirely dark brown ( Fig. 56 ); dorsal face of T1 coarsely punctate anteriorly ( Fig. 59 )................................................................................... 15

15 Subbasal area of S7 of ♂ with pair of triangular teeth ( Fig. 64 ); transverse rim at junction of anterior and dorsal faces of T1 present ( Figs 4 , 59 ); clypeus moderately punctate medially ( Fig. 62 ); Laos, * Vietnam...................................................................................................... A. quadrimaculatum Gusenleitner, 1997

- Subbasal area of S7 of ♂ with pair of flat lobe-shaped protuberances ( Fig. 12 in Girish Kumar & Sharma 2015); transverse rim at junction of anterior and dorsal faces of T1 absent ( Fig. 37 ); clypeus rugose-punctate medially ( Fig. 38 ); [apex of T1 and T2 with yellow or dull reddish yellow band (sometimes medially interrupted)]; India (Meghalaya, Sikkim) , China (* Yunnan).............................................................................. A. lugubrinum ( Cameron, 1900)

Figures

FIGURES 27–32. Allorhynchium diffinis (Giordani Soika), ♀, holotype. 27, wings; 28, head and mesosoma, lateral aspect; 29, mesosoma and first metasomal tergum, dorsal aspect; 30, metasoma, dorsal aspect; 31, head, anterior aspect; 32, head and pronotum, dorsal aspect.

FIGURES 1, 2. Allorhynchium diffinis (Giordani Soika), ♀, holotype. 2, Habitus, dorsal aspect; 3, ibid., lateral aspect.

FIGURES 41–48. Allorhynchium metallicum (de Saussure), ♂, China (Tibet). 41, head and pronotum, lateral aspect; 42, propodeum and base of metasoma, dorsal aspect; 43, ibid., latero-dorsal aspect; 44, terminal sternum (S7), lateral view; 45, head, anterior aspect; 46, head and pronotum, dorsal aspect; 47, propodeum, posterior aspect; 48, apex of antenna.

FIGURES 49–55. Allorhynchium metallicum (de Saussure), ♀, China (Yunnan). 49, wings; 50, head and pronotum, lateral aspect; 51, propodeum and base of metasoma, latero-dorsal aspect; 52, ibid., dorsal aspect; 53, head, anterior aspect; 54, head and pronotum, dorsal aspect; 55, propodeum, caudal aspect.

FIGURES 56–65. Allorhynchium quadrimaculatum Gusenleitner, ♂, Vietnam. 56, wings; 57, head and mesosoma, lateral aspect; 58, mesosoma, dorsal aspect; 59, propodeum and metasoma, lateral aspect; 60, metasoma, lateral aspect; 61, antenna; 62, head, anterior aspect; 63, head and pronotum, dorsal aspect; 64, terminal sternum (S7), latero-ventral aspect; 65, apex of antenna.

FIGURES 3, 4. Allorhynchium spp., habitus, lateral aspect. 3, A. lugubrinum (Cameron, 1900), ♀, China; 4, A. quadrimaculatum Gusenleitner, ♂, Vietnam.

FIGURES 13–19. Allorhynchium chinense (de Saussure), ♂, China (Henan). 13, head and mesosoma, lateral aspect; 14, propodeum and metasoma, dorsal aspect; 15, propodeum, latero-dorsal aspect; 16, terminal sternum (S7), lateral aspect; 17, head, anterior aspect; 18, head and pronotum, dorsal aspect; 19, propodeum, posterior aspect.

FIGURES 20–26. Allorhynchium chinense (de Saussure), ♀, China (Jiangxi). 20, wings; 21, head and mesosoma, lateral aspect; 22, propodeum and metasoma, dorsal aspect; 23, propodeum, latero-dorsal aspect; 24, propodeum, posterior aspect; 25, head, anterior aspect; 26, head and pronotum, dorsal aspect.

FIGURES 5–12. Allorhynchium argentatum (Fabricius), ♂, Indonesia (Sumatra). 5, wings; 6, head and mesosoma, lateral aspect; 7, mesosoma, dorsal aspect; 8, metasoma, lateral aspect; 9, head, anterior aspect; 10, head and pronotum, dorsal aspect; 11, antenna; 12, base of antenna.

FIGURES 66–71. 66, Allorhynchium concolor van der Vecht, ♀, paratype, Indonesia, head, anterior aspect. 67–69, A. snelleni (de Saussure), ♀ (66, Bawean) and ♂ (68, 69), ibid., but 69 detail of clypeus. 70, 71, A. vollenhoveni (de Saussure), ♀, Indonesia, ibid., but 61 detail of clypeus.

FIGURES 33–40. Allorhynchium lugubrinum (Cameron, 1900), ♀. 33, right forewing; 34, head and part of mesosoma, lateral aspect; 35, ibid., dorsal aspect; 36, metasoma, lateral aspect; 37, ibid., dorsal aspect; 38, head, anterior aspect; 39, head and pronotum, dorsal aspect; 40, mesosoma, lateral aspect.