Xanthophius gutianshanensis, Zhou, Yu-Lingzi & Zhou, Hong-Zhang, 2013

Zhou, Yu-Lingzi & Zhou, Hong-Zhang, 2013, Two new species of Xanthophius Motschulsky (Coleoptera: Staphylinidae, Staphylininae, Xantholinini) from China with notes on X. filum (Kraatz), Zootaxa 3626 (3), pp. 363-380 : 367-370

1. Xanthophius gutianshanensis sp. n.

( Fig. 3 A–G; Fig. 4 A–F)

Type material. Holotype: male, CHINA: Zhejiang: Kaihua Co.: Gutianshan, 446–715 m, 1–4.V.2010, Liu Chongling collected (IZ-CAS); paratypes: 6 females, 12 males, same data as holotype; 8 males, same data as holotype except Yu Xiaodong collected; 1 male, same data as holotype except 5–8.VII.2009 (IZ-CAS).

Description.

Measurement (N=3). BL= 4.07–4.81 mm, FL= 2.07–2.41 mm, HL= 0.62–0.72 mm, HW= 0.49–0.58 mm, PL= 0.70–0.80 mm, PW= 0.45–0.53 mm, EL= 0.68–0.80 mm, EW= 0.60–0.70 mm.

Body nearly cylindrical and small sized. Entirely brown, except head slight darker; antennae, maxillary and labial palpi, and legs light brown. Sometimes body dark brown, with darker head and lighter elytra; antennae, maxillary and labial palpi, and legs brown.

Head ( Fig. 4 A). Subrectangular (HL to HW ratio 1.25), tempora slightly widened posteriorly, posterior angles rounded. Dorsal integument bearing no micropunctures and microsculpture, but with extensively distributed medium-sized punctures, puncture intervals equal to 2–3 punctures’ diameter, except more closer near anteocular furrows. Median longitudinal region impunctate, width ca. 0.1 mm; deflexed portion of tempora with 4 rows of medium-sized punctures. Each side of cranium with a puncture on epistoma, 3–4 punctures located in frontal furrow, an anterolateral puncture near antennal insertion, a midlateral puncture about a distance of 3–4 punctures’ diameter from dorsal margin of eye, temporal puncture and occipital puncture not apparent. Frontal furrows relatively long, longer than the length of eye; anteocular furrows distinct and long, with 2–3 smaller punctures, and with an oblique row composed of 2–4 medium-sized punctures behind. Eye medium-sized, slightly shorter than half the length of tempora (eye: tempora = 0.18: 0.39 mm). Epistoma narrowed forwards. Distance between antennal insertions (0.16 mm) being larger than that from antenna to eye (0.10 mm).

Antennae. Scape stout, thickened apically, much longer than three subsequent antennomeres combined, 0.24 mm; antennomere II elongate, 0.08 mm; III slightly elongate or subquadrate, much shorter than II, 0.05 mm; IV and V transverse, length of 0.04 mm; last antennomere elongate, 0.11 mm, equal to length of two preceding antennomeres combined.

Mouthparts. Labrum transverse and bilobed. Mandibles falciform, left one with a small tooth on anterior 1/3 of inner edge. Maxillary palpus stocky, 3nd segment longest, last segment aciculate, not distinctly longer than the penultimate. Labial palpus slender, last segment longest and aciculate.

Neck. Wide (0.20 mm), narrower than half the width of head.

Pronotum ( Fig. 4 B). Subrectangular, elongate (PL to PW ratio 1.55), longer and slightly narrower than head. Anterior angle well-defined and protruding laterally, lateral margins slightly sinuate, widest at anterior 1/3 and narrowest at posterior 1/3, posterior angles broadly rounded. Dorsal integument without micrsculpture, but bearing a pair of admedian row of 12–14 punctures, a pair of lateral rows of 8–9 punctures, and also a few irregular punctures near anterior and lateral margins of pronotum.

Elytra ( Fig. 4 C). Subrectangular (EL to EW ratio 1.13), slightly shorter than pronotum, but apparently wider. Humeri well developed, lateral margins divergent posteriorly, hind margin rounded. Dorsal integument bearing 5–6 rows of punctures on each elytron, interspaces between rows of ca. 1–2 punctures’ diameter; deflexed portion of each elytron with 2–3 rows of denser punctures.

Legs. First four segments of protarsi stout but not dilated, and those of meso- and metatarsi not slender. Last segment equal to length of II–IV combined, respectively.

Abdomen. Cylindrical, broadest at segment VII. Tergites III–VII slightly shiny, each segment covered with sparse, shallow, transverse microstriae, and with small punctures, puncture intervals about 2–3 punctures’ diameter. Each tergite without a basal impression near anterior margin. All abdominal sternites shiny, with microstriae and punctures as those on tergites.

Male ( Fig. 3 A–G; Fig. 4 D–F). Abdominal segment VIII entirely covered with punctures, posterior margin subtruncated ( Fig. 3 A, B). Tergite IX symmetrical, connected mediobasally. Sternite IX asymmetrical, widest at anterior 1/3, with linear-shaped base, and angulate apex ( Fig. 3 D). Tergite X symmetrical, with relatively broad and subtruncated base, broadest at apical 1/4, gradually narrowed to connect slightly rounded posterior margin ( Fig. 3 C). Aedeagus small ( Fig. 3 E; Fig. 4 D), basal bulb subspherical, 0.42 mm long. Parameres symmetrical, not attached to basal bulb, distinctly elongate, 0.37 mm long and extended to dorsal side ( Fig. 3 F), slightly shorter than the length of basal bulb. Internal sac (endophallus) corkscrew-like ( Fig. 4 G), apical third bearing three processes; surface of basal half more sclerotized, folded with a larger process inside.

Distribution. China (Zhejiang: Kaihua co.).

Etymology. The specific epithet is named after the Chinese name (Pin-yin) of the type locality, Gutianshan.

Remarks. We illustrated the morphology of the endophallus in situ in Fig. 4 E, from fresh specimen, of which membranous structures have been torn off and basal spines of endophallus (bs) have been artificially scattered; bs are located in apical portion, comprising five pairs of small spines; subapical spines of endophallus (sas) are formed by a tuft of smaller, lighter-coloured spines in the middle; apical sclerotized structure of endophallus (ass) is composes of a large, dark-coloured, curved sclerite, which is situated in basal 1/3. Compared with bs of X. filum ( Fig. 9 ), they are similar in morphology to those of the new species but differ in the number of the spines, which cannot be seen in dry specimens. It also can be distinguished from X. unicidentatus sp. n. by tempora more widened posteriorly, anteocular furrows longer, with an oblique row composed of 2–4 medium-sized punctures behind anteocular furrow, admedian row on pronotum consisting of 12–14 punctures, and tergites III–VII covered with sparse, shallow, transverse microstriae.

Figures

FIGURE 3. Xanthophius gutianshanensis sp. n.: A. male tergite VIII; B. male sternite VIII; C. male tergite X; D. male sternite IX; E. aedeagus, ventral view; F. right paramere, dorsal view; G. endophallus at rest, ventral view. Scale bars 0.15 mm.

FIGURE 4. Xanthophius gutianshanensis sp. n.: A. head; B. pronotum; C. elytra; D. aedeagus, ventral view; E. dissected endophallus with scattered bs; F. endophallus everting, lateral view. Scale bars 0.30 mm.

FIGURE 9. Sclerotized structures of everted endophallus of Xanthophius filum (Kraatz). A. from ventral view; B. from dorsal view.