Xenanastatus imbricatius Wu & Peng, 2023

Wu, Tong, Ni, Yuanzhou, Wang, Zongying & Peng, Lingfei, 2023, First record of Xenanastatus Bouček (Hymenoptera: Eupelmidae) in China with description of one new species with DNA data, Zootaxa 5374 (4), pp. 585-593 : 588-592

Xenanastatus imbricatius Wu & Peng sp. nov.

Figs 1‒4

Diagnosis. Head with scrobal depression mostly imbricate ( Figs 1C, F ), not reaching anterior ocellus ( Fig. 1C ); metacoxa with basal three-fourth dark with blue metallic luster ( Fig. 3A ); PMV slightly longer than 4× STV ( Fig. 2C ); metatarsus with basal three tarsomeres white and apical two tarsomeres yellowish-brown ( Fig. 3B ); ovipositor sheaths shorter than gaster and in dorsal view with exposed part bicolored, yellowish-brown within basal one-tenth and remainder dark brown ( Fig. 3E ), though in lateral view extreme base also dark under gastral apex ( Fig. 3C ).

Etymology. The species name is from the Latin imbricatus (tiled, with overlapping tiles), in reference to the imbricate sculpture of the scrobal depression.

Type material. Holotype (♀, FAFU): CHINA, Lutian village, Foshan City, Guangdong Prov , 18 Oct.–18 Nov. 2021, DNA number: 951, Malaise trap . Paratype (1♀, FAFU): CHINA, Dadongshan natural reserve, Lianzhou, Qingyuan City , Guangdong Prov , 24 May–6 Jun. 2021, DNA number: 956, Malaise trap .

Description (Holotype). FEMALE ( Fig. 1A ). Length, including ovipositor sheaths, about 5.0 mm.

Head. Face ( Fig. 1C ) mostly bright blue with metallic luster under some angles of light; frons ( Fig. 1F ) and vertex ( Fig. 1D ) extensively dark purple or slightly green under some angles of light, and with dark brown hairlike setae; occiput and scrobal depression bright blue ( Figs 1C, D ); parascrobal region and margin of torulus green with slight golden metallic luster, parascrobal region with one row of white lanceolate setae ( Figs 1C, E ); lower face ( Fig. 1E ) bright blue to green with golden reflections with white lanceolate setae; gena ( Fig. 1B ) golden-green with white lanceolate setae anteriorly and dark brown hairlike setae posteriorly; mandibles and maxillary and labial palps dark brown ( Fig. 1B ). Antenna ( Fig. 1G ) dark brown, scape with distinct metallic luster and some white hairlike setae.

Head in frontal view ( Fig. 1C ) 1.3× as wide as high, distance between toruli 0.8× distance between torulus and clypeus margin ( Fig. 1E ), distance between eyes below 1.8× distance between eyes above; in lateral view ( Fig. 1B ) subspheroidal with margin of torulus slightly convex, malar space 0.5× eye height; in dorsal view ( Fig. 1D ) width 1.4× length, with interocular distance about 0.1× head width; OOL: POL: LOL: MPOD = 0.5: 1.2: 1.2: 1.0. Face ( Fig. 1C ) with parascrobal region very narrow medially, almost reaching inner orbit; interantennal prominence small and reticulate ( Fig. 1E ); scrobal depression ( Fig. 1C ) deep and ∩-like, imbricate to reticulate, only lower part magined, dorsal margin delimited but smoothly curved into frontovertex, separated from anterior ocellus by distance equal to 3.2× longitudinal diameter of anterior ocellus; lower orbit above level of dorsal margin of torulus; lower face ( Fig. 1E ) reticulate-imbricate; frons ( Fig. 1F ) coriaceous; vertex ( Fig. 1D ) coriaceous to reticulate; temple ( Fig. 1B ) coriaceous-alutaceous. Mandible tridentate. Antenna ( Fig. 1G ) with scape compressed-subrectangular, 3× as long as wide.

Mesosoma. Elongate, dark with some distinct metallic lusters; pronotum with violaceous reflections medially and bright blue reflections posteriorly; mesonotum with median lobe slightly violet and posterior depressed region with bright blue metallic luster; outer margin of lateral lobes with white hairlike setae; prepectus with anterior surface bright blue and lateral surface dark brown ( Fig. 1H ); tegula dark with 3 brown hairlike setae; mesepisternum extensive blue with white hairlike setae ( Fig. 1H ); acropleuron mostly dark brown, anteriorly bright blue ( Fig. 1H ). Macropterous. Fore wing ( Fig. 2A ) with alternating infuscate and hyaline bands—extreme base of basal cell infuscate but most of basal cell hyaline to level of base of parastigma, infuscate behind parastigma and about basal two-thirds of marginal vein, hyaline behind about apical one-third of marginal vein to about apex of stigmal vein with margins slightly incurved toward each other mesally, and infuscate beyond level of stigmal vein; setose except costal cell partly bare, with hyaline regions with white setae and infuscate regions with dark setae; setose except costal cell partly bare ( Fig. 2B ). Legs with all femora similarly dark except mesofemur pale white apically; protibia and metatibia similar in color pattern, mostly brown but pale apically ( Fig. 2D ); protarsus with apical tarsomere and basal two tarsomeres brown but third and fourth tarsomeres yellow ( Fig. 2D ); mesotibia brown and mesotarsus ( Fig. 3D ) dark brown; metacoxa with dense white lanceolate setae, basal three-fourths dark with blue luster and apical one-fourth pale white ( Fig. 3A ); metatarsus with basal three tarsomeres pale white and apical two tarsomeres yellow to brownish ( Fig. 3B ). Scutellum and axillae dark with blue, green and slight coppery luster ( Fig. 1I ). Propodeum dark with blue metallic luster, callus with white hairlike setae laterally ( Fig. 1I ).

Pronotum reticulate. Mesoscutum reticulate-coriaceous, slightly convex anteriorly and concave posteriorly, with anteromedian lobe relatively short and lateral lobe carinate posteriorly. Scutellar-axillar complex ( Fig. 1I ) low convex, scutellum elongate, 1.5× as long as broad, with brown hairlike setae, coriaceous to reticulate; axillae with inner angles distinctly separate anteriorly. Mesopectus coriaceous-reticulate anterior of acropleural sulcus, acropleuron very finely longitudinally coriaceous to slightly reticulate ( Fig. 1H ). Fore wing ( Fig. 2A ) extended to apex of Gt5; CC: MV: PMV: STV = 15.0: 16.8: 4.8: 1.0; apex of stigmal vein slightly curved toward postmarginal vein ( Fig. 2C ). Mesotibia without apical groove, with 15 dark pegs apically arranged in about 3 overlapping rows ( Fig. 3D ); mesotarsus with basal 4 tarsomeres with row of dark pegs along each lateral margin, the fourth tarsomere with 5 pegs ( Fig. 3D ). Metanotum very narrow, V-like angulate and recurved, pouch-like, over apex of scutellum ( Fig. 1I ). Propodeum flat and long; plical region trapezoidal, concave mediolongitudinally within anterior half and distinctly separated from smooth and bare callus ( Fig. 1I ).

Gaster. ( Fig. 3E ) Mostly dark with variably extensive luster, Gt1 and Gt2 dark to brown and Gt6 dark with purple and blue reflection; Gt1 with lanceolate setae on both lateral sides. Ovipositor sheaths in dorsal view ( Fig. 3E ) with exposed part bicolored, the basal one-tenth yellowish-brown and remainder dark brown, but in lateral view with region under gastral apex also dark brown ( Fig. 3C ).

Gaster similar in length to combined length of head and mesosoma, smooth to finely coriaceous ( Fig. 3E ); Gt1 and Gt2 with deeply emarginate and Gt3‒Gt5 with slightly emarginate posterior margins; Gt3‒Gt5 with fine mediolongitudinal sulcus; Gt6 broadly exposed, not medially divided ( Fig. 3E ); Gt6 and syntergum in dorsal view with posterior margin rounded ( Fig. 3E ). Ovipositor sheaths exserted, similar in length to metatibia.

MALE. Unknown.

Variation. Body length of the paratype is about 6.3 mm ( Fig. 4A ); the frons varies in sculpture from smooth to coriaceous ( Figs 4B, F ). Gt6 with distinctly golden-green metallic luster ( Figs 4A, E ).

Distribution. CHINA: Guangdong (Oriental Region).

Sequence data. The accession number and length of sequence of the three gene sequences are given in Table 2 .

Remarks. Based on the key to females of Xenanastatus by Narendran (1998) females of X. imbricatius are similar to X. padus in structure of the scrobal depression, but the ovipositor sheaths of the latter species are mostly pale beyond the syntergum and much shorter than the gaster ( Narendran 1998, fig.1). Further, the basal one-fourth of the metacoxa of X. padus was described as pale white and the mesosoma as “smoothly sculptured, shining”. According to the description and drawing of the scrobal depression by Narendran (1998), females of X. imbricatius are easily differentiated from X. keralicus . The scrobal depression of the latter species was described as “narrowly reaching front ocellus”; the drawing ( Narendran 1998, fig. 5) shows an outline that dorsally converges, sinuately, toward the anterior ocellus to form something like the neck of a bottle. This shape is an unusual characteristic and, as such, might be an artefact, but two characters, the color pattern of the metatarsus and the relative length of the STV to the PMV easily distinguish females of the two species.

Figures

FIGURE 1. Xenanastatus imbricatius Wu & Peng (holotype, ♀). A, body, dorsal view; B, head, lateral view; C, head, front view; D, head, dorsal view; E, lower face; F, frons (enlarged); G, antenna; H, mesosoma, lateral view; I, scutellar-axillar complex, metanotum and propodeum, dorsal view. Vertical lines in G indicate apical margin of preclaval flagellomeres.

FIGURE 2. Xenanastatus imbricatius Wu & Peng (holotype, ♀). A, fore wing; B, costal cell and submarginal vein; C, stigmal and postmarginal veins; D, protibia and protarsus. Arrow in C points to apex of stigmal vein.

FIGURE 3. Xenanastatus imbricatius Wu & Peng (holotype, ♀). A, metacoxa and metafemur; B, metatarsus; C, ovipositor sheaths, lateral view; D, mesotarsus; E, gaster and ovipositor sheaths, dorsal view.

FIGURE 4. Xenanastatus imbricatius Wu & Peng (paratype, ♀). A, body, dorsal view; B, head, front view; C, mesosoma, dorsal view; D, lower face; E, ovipositor sheaths (broken), lateral view; F, frons (enlarged).