Xiphydria melanoptera Shinohara, Hara and Smith, 2020

Peeran, Syed Wali, Murugan, Manohar, Doggalli, Nagabhushana, Fageeh, Hytham, Ibrahim, Wael, Al-Ak'hali, Mohammed Sultan & Basheer, Syed Nahid, 2024, Records of Four Xiphydriidae (Hymenoptera) Collected in Traps in Japan, with Notes on Xiphydria melanoptera, Bulletin of the National Museum of Nature and Science. Series A, Zoology 50 (2), pp. 75-79 : 76-79

Xiphydria melanoptera Shinohara, Hara and Smith, 2020

( Figs. 1 , 2 )

Xiphydria melanoptera Shinohara et al., 2020: 387 .

Specimens examined. HOKKAIDO: 2 ♀3 ♂, Nakasatsunai , Riv. Satsunai, 12–14. VIII. 1996, Lubomir Masner, Kenzo Yamagishi ( YPT) .

Distribution. Japan (Hokkaido).

Male (hitherto undescribed, Fig. 2 ). Length about 5–8 mm. Black; lateral part of clypeus yellow or pale brown ( Fig. 2C, I, J ); ventral pit of malar space and narrow ventral margin of gena obscurely marked with pale brown; lower inner orbit adjacent to clypeus yellow in one specimen ( Fig. 2J ); mandible yellow, apically blackish; antenna with scape and pedicel dark brown and flagellum blackish brown; legs dark brown, partly blackish; wings distinctly stained with black, apical 1/3 becoming hyaline; veins and stigma blackish brown. Antenna ( Fig. 2D ) with 15 or 16 antennomeres; abdominal sterna 6–8 each with group of long golden hairs on posterior part medially (hairs longer on sterna 7 and 8, Fig. 2G ); tergum 9 without distinct median longitudinal keel, rounded at apex ( Fig. 2F ); subgenital plate broad, apical margin roundly incised at middle ( Fig. 2H ).

Remarks. This is an extremely rare species so far known only from the holotype from Hokkaido, Japan (Shinohara et al., 2020). It is close to X. kastsheevi Ermolenko, 1979 , which is also known only from the holotype obtained in Primorskij kraj, Russia ( Ermolenko, 1979). In the key to the species of the Xiphydria annulitibia group by Shinohara et al. (2020), the two females listed above go to couplet 4 ( X. melanoptera and X. kastsheevi ) but do not exactly match either of the two species. In this key, which was actually based on the examination of the holotype of X. melanoptera and the original description of X. kastsheevi ( Ermolenko, 1979, the holotype not examined), the two species were separated by the number of antennomeres (19 or 20 in X. melanoptera and 15 in X. kastsheevi ), presence or absence of white lateral spots on the abdominal terga 2 and 3 (present in X. melanoptera and absent in X. kastsheevi ), and shape of the abdominal tergum 10 (distinctly directed dorsally at apex in lateral view in X. melanoptera and not so in X. kastsheevi ). The two females from Nakasatsunai have 16 or 17 antennomeres and the white lateral spots are present on tergum 2 but absent on tergum 3. The difference in the shape of the abdominal tergum 10 is not clear ( Fig. 1 ). Therefore, these two species cannot be clearly separated by these characters only. On the other hand, with the additional material, we have found a probable interspecific difference between the two taxa in the shape of the apical ovipositor sheath. It is long and slender, about 3.7–4.1 times as long as wide in X. melanoptera ( Fig. 1A–C ), whereas it is short and thick, about 2.9 times as long as wide in X. kastsheevi ( Fig. 1D ). Though we need more material and an examination of the holotype of X. kastsheevi to ascertain the relationship of the two taxa, here we treat X. melanoptera as a distinct species.

The two females from Nakasatsunai are similar to the holotype of X. melanoptera except for the differences given above and smaller size. They are about 7 mm and 8.5 mm long without ovipositors, whereas the holotype is about 10.5 mm. The previously unknown male ( Fig. 2 ) is distinguished from the related species by the black head, thorax and abdomen, with lateral part of the clypeus, malar space, ventral margin of the gena and sometimes the lower inner orbit marked with pale brown ( Fig. 2C, I, J ), the blackish and apically more hyaline wings ( Fig. 2A ), presence of groups of long setae on the abdominal sterna 6–8 ( Fig. 2G ), and the tergum 9 without a distinct median longitudinal keel ( Fig. 2F ).

It is interesting to note that all the specimens of X. melanoptera were collected in traps in southern Hokkaido in mid-August; the holotype was collected in a Malaise trap in Muroran during August 12–19, 2007 , and the newly studied material, two females and three males, was collected in yellow pan traps in Nakasatsunai during August 12–14, 1996 .

Shinohara (2022) noted that most of the known specimens of two rare southern Japanese xiphydriid woodwasps, Indoxiphia prima Smith, 2019 , and Lissoxiphyda mitai Shinohara, 2020 , were collected in yellow pan traps. Commoner xiphydriids in northern and central Japan, e.g., Xiphydria camelus (Linné, 1758) and its allies (or the X. camelus complex), are almost exclusively found on dead wood or branches, rarely on foliage. Males of some southern Japanese xiphydriids are collected almost exclusively by sweeping foliage, not on dead wood (Shinohara, unpublished observation). However, all those species, or Xiphydriidae in general, are seldom collected in traps, particularly in yellow pan traps; of the 964 specimens of X. camelus complex examined by Shinohara and Kameda (2019), only one was collected in a Malaise trap and none in yellow pan traps according to the label data.

Xiphydria melanoptera , I. prima and L. mitai are all small-sized xiphydriids and males are unknown for the latter two species. It is quite likely that they have some peculiar biological and behavioral traits in common, which cause them almost never to be found on dead wood or on foliage, but more frequently caught in traps.

Figures

Fig. 1. Apical part of abdomen, lateral view, Xiphydria melanoptera (A–C) and X. kastsheevi (D).—A, Holotype, reproduced from Shinohara et al., 2020, laterally reversed; B, C, specimens from Nakasatsunai; D, holotype, reproduced from Ermolenko (1979).

Fig. 2. Xiphydria melanoptera, male, three specimens (A–H, I and J) from Nakasatsunai. — A, Lateral view; B, head, dorsofrontal view; C, head, frontal view; D, antenna; E, head and thorax, lateral view; F, apex of abdomen, dorsal view; G, apex of abdomen, lateral view, arrows showing hair groups on sterna 7 and 8; H, apex of abdomen, ventral view; I, J, head, laterofrontal view.