Xiphydria annulitibia, Takeuchi, 1936

Shinohara, Akihiko, Hara, Hideho & Smith, David R., 2020, The Xiphydria annulitibia group in northeastern Asia (Hymenoptera, Xiphydriidae), Zootaxa 4755 (2), pp. 375-389 : 376

Xiphydria annulitibia group

Species of the X. annulitibia group are characterized as follows: Small to medium-sized xiphydriids, varying from 6.5 to 15.5 mm without ovipositor in female and from 6.5 to 12.5 mm in male. Black, with whitish marks usually on head, legs and lateral part of abdomen ( Figs 1 , 2). No reddish- brown or yellowish areas. In some species, wings partly blackish.

This species group is rather loosely defined by overall similarities and possibly phylogenetically heterogeneous, without any evidence of monophyly. However, the species of this group may differ from the members of the X. camelus group ( Shinohara & Kameda 2019) by their comparatively small size, the absence of reddish brown areas on the legs and the presence of hair tufts on the male abdominal sterna and from the members of the X. palaeanarctica group (Shinohara 2019) by their comparatively small size and the absence of whitish areas on the antennae.

The five constituent species of the X. annulitibia group may be divided into three subgroups, X. annulitibia subgroup ( X. annulitibia only), X. kanba subgroup ( X. kanba only) and X. kastsheevi subgroup ( X. kastsheevi , X. konishii and X. melanoptera n. sp.), each possessing peculiar features as shown in the key below.

The maxillary palpus usually with four palpomeres and usually open cell 3R 1 in the forewing and open cell R 1 in the hindwing in X. annulitibia are quite peculiar among the members of Xiphydria , and it may be tempting to establish a new genus for X. annulitibia . However, easy proposal of a new genus for a single species with a few peculiar features may only proliferate monotypic genera in our system. We leave this species in Xiphydria until more evidence becomes available.

Key to females of Xiphydria annulitibia group (males are known only for X. kanba )

1. Head capsule all black ( Fig. 3 A–C) (rarely with paired small obscure spots on anterior part of vertex); maxillary palpus with 4 or occasionally 5 palpomeres; wings hyaline, uniformly very slightly stained with blackish brown ( Fig. 4A ); cell 3R 1 in forewing and cell R 1 in hindwing very narrowly open at apex (rarely closed) ( Fig. 4A ); abdominal tergum 2 without pale spot laterally ( Fig. 1A ). X. annulitibia subgroup...................................................... X. annulitibia

-- Head capsule with pale spots at least along lower inner orbits and lower gena ( Figs 2 D–F, 3D–L); maxillary palpus with 5 palpomeres; wings hyaline with slight infuscation in apical 1/3 (darkest below stigma) ( Fig. 2A ) or rather strongly stained with black (apical part weakly so) ( Fig. 1 B–F); cell 3R 1 in forewing and cell R 1 in hindwing closed at apex ( Figs 1D , 2A, 4B); abdominal tergum 2 usually with pale spot laterally ( Figs 1 C–F, 2B)............................................. 2

2. Clypeus entirely black ( Figs 2E , 3E ); wings hyaline with slight infuscation in apical 1/3 (darkest below stigma) ( Fig. 2A ); forewing with cell 2Rs much narrower than cell 1M ( Fig. 4B ); crossvein 2r-m usually apical to crossvein 2m-cu on vein M ( Fig. 4B ); abdominal tergum 9 (and usually also tergum 8) entirely black without pale spots ( Fig. 5B ). X. kanba subgroup................................................................................................... X. kanba

-- Clypeus with whitish marks, at least laterally ( Fig. 3H, K ); wings rather strongly stained with black (apical part weakly so) ( Fig. 1 B–F); forewing with cell 2Rs about as wide as cell 1M ( Fig. 4A ); crossvein 2r-m usually basal to crossvein 2m-cu on vein M ( Fig. 4A ); abdominal terga 8 and 9 with pale areas along lateral posterior margins ( Figs 1 C–F; 5A, C, D). X. kastsheevi subgroup........................................................................................... 3

3. Clypeus, supraclypeal area and malar space yellowish white ( Fig. 3H, I ). [Antenna with 15–17 antennomeres (n=6); abdominal terga 2 and 3 with whitish lateral spots; abdominal tergum 10 not distinctly directed dorsally at apex in lateral view ( Fig. 5C ).]....................................................................................... X. konishii

-- Median part of clypeus, supraclypeal area and dorsal margin of malar space mostly black ( Fig. 3K, L ).................. 4

4. Antenna with 19 or 20 antennomeres (n=2); abdominal terga 2 and 3 with whitish lateral spots; abdominal tergum 10 distinctly directed dorsally at apex in lateral view ( Fig. 5D )................................................ X. melanoptera

-- Antenna with 15 antennomeres; abdominal terga 2 and 3 without whitish lateral spots; abdominal tergum 10 not distinctly directed dorsally at apex in lateral view (fig. 7 in Ermolenko 1979)..................................... X. kastsheevi

Figures

FIG. 1. Xiphydria spp., females.—A, X. annulitibia, holotype; B, C, X. konishii, paratype, Bibai; D, X. konishii, holotype; E, X. konishii, paratype, Take; F, X. melanoptera, holotype.

FIG. 3. Heads, females, Xiphydria annulitibia, holotype (A–C), X. kanba, holotype (D–F), X. konishii, holotype (G–I) and X. melanoptera, holotype (J–L).—A, D, G, J, Dorsal view; B, E, H, K, frontal view; C, F, I, L, frontolateral view.

FIG. 4. Xiphydria annulitibia (A) and X. kanba (B), females, holotypes, wings, with names of cells (A) and veins and crossveins (B). Four large arrows show open or nearly open (A) or closed (B) apices of cell 3R1 in forewing and cell R1 in hindwing.

FIG. 2. Xiphydria kanba, female (A–F) and male (G–M), paratopotypes.—A, G, Dorsal view; B, H, I, lateral view (I, showing lateral pale spots on abdomen); C, J, ventral view; D, K, head, dorsal view; E, L, head, frontal view; F, M, head lateral view.

FIG. 5. Apical parts of abdomens, holotypes, lateral view.—A, Xiphydria annulitibia; B, X. kanba; C, X. konishii; D, X. melanoptera.