Himaloaesalus gaoligongshanus Huang and Chen, 2016

Huang, Hao & Chen, Chang-Chin, 2016, Two new species of stag beetles (Coleoptera: Lucanidae) from western Yunnan, China, Insecta Mundi 2016 (516), pp. 1-8 : 2-3

Himaloaesalus gaoligongshanus Huang and Chen , new species

( Fig. 1 –21)

Type material. Holotype ( Fig. 1–3 , 9–11 , 15–20): YUNNAN: ♂, Tengchong County, on road between Tengchong and Baoshan, Nankang Pass, ca. 2000m, 4.V.2012, Xiao-Dong Yang leg. ( SHNU) . Paratypes: YUNNAN: 1 ♂, 3 ♀♀, same data as for the holotype (1 ♀ in CHH, 1 ♂, 2 ♀♀ in CCCC) ; 3 ♂♂, Tengchong County, Zizhi Township , ca. 1800m, V.2014, Z. Peng leg. (all in CHH) ; 3 ♂♂, 3 ♀♀, Gongshan County, Dulongjiang, Xianghong village , VII.2015, X.-D. Yang leg. (1 ♂ in BMNH, 2 ♂♂, 3 ♀♀ in CCCC) .

Holotype description. Length of pronotum-elytra measured from apex of pronotum to the caudal end of elytra: 6.5 mm. Ground color of the whole body on both surfaces dark reddish brown. Bristles on dorsal surface of the body dark brown. Bristles on ventral surface of the body bright yellow. Head. Width approximately half as wide as pronotum. Interocular width about 4 times as wide as eye. Anterior portion of head in front of eye nearly as long as eye. Intermandibular projection rounded, not angled. Canthus present and slightly projecting beyond eye. Left mandible with a subapical dorsal tooth and a subapical ventral tooth. Right mandible with a subapical dorsal tooth but without ventral tooth. Both mandibles with mola well developed and massive in inner lateral view, and each with a setose prostheca along median edge. Labrum setose, movable and nearly 2/9 times as wide as head. Galea of maxilla with setae on apex not regularly curved or brush-like. Lacinia of maxilla free and easily recognizable. Ligula bilobed and setose. Base of labial palpomere 1 concealed by mentum. Palp insertions on prementum close to each other. Antenna partially geniculate and composed of ten antennomeres. Antennal scape without longitudinal groove. Antennal club composed of the last three antennomeres and completely pubescent. Antennomere 3 elongate, nearly twice as long as wide. Mentum transverse and rounded at lateral corners, setose and coarsely punctate at surface, and with lateral margins nearly straight and convergent anteriorly. Thorax and abdomen. Ratio of pronotum-elytra-length to elytrawidth: 1.72. Dorsal line of elytra in lateral view evenly convex. Pronotum and elytra densely punctate, with punctures irregularly distributed, not serially in longitudinal lines. Scutellum slightly longer than wide. Intercoxal process of prosternum plate-like, slightly convex in lateral view, with posterior margin projecting almost as far as procoxae, lacking step-like projection posteriorly. Metasternum and abdominal ventrites without sulci. Posterior margin of the last visible abdominal ventrite rounded, but rather flat near center. Semicircular punctures along the anterior margin of the abdominal ventrites 3–5 markedly broader than those of the abdominal ventrites 1–2. Surface structures. Vestiture of pronotum and elytra consisting of two types of elements: scale-like bristles and irregularly branched tomenta. Bristles longitudinally ribbed, inserted anteriorly in the wall of the punctures, concentrated into clumps. Tomenta arising anteriorly in the wall of the punctures. All punctures sub-equal in size, with margins sharply defined, and with floor raised and polygonally sculptured. Puncture of bristle associated with a tubercle outside of puncture. Legs. Protibia markedly broadened from base to apex, with a minute inner terminal spur, an outer apical spine and 2 smaller spines on outer lateral margin, and with seta-tuft along the inner lateral margin near apex. Apical spine curved and nearly half as long as the width of protibia at apex. Mesotibia with 2 small spines externally. Metatibia with 2–3 small spines externally. Tarsus short, half as long as respective tibiae. Male genitalia (Fig. 15 – 20). Abdominal segment 9 slender and elongate; basal lobe present but rather short; paired pleurites plate-like and protruding ventrally; dorsal plate pigmented. Basal piece rather long, slightly shorter than parameres. Parameres nearly half as long as median lobe. Median lobe gently curved and gradually widened from base to apex in lateral view, generally tuber-like in dorsal view, asymmetrical and with a long sclerite originating from left side of dorsal surface. Internal sac bilobed and L-shaped.

Description of male paratypes. Length from apex of pronotum to the caudal end of elytra was 5.3 – 6.7 mm .. Individual variation is only found in the color of the body on both surfaces and the length of canthus. There is no variation in the male genitalia.

Description of female paratypes. Length from apex of pronotum to the caudal end of elytra was 6.3 – 6.9 mm .. Sexual dimorphism in external morphology is very weak. A difference is only found in the apex of the metatibia, which is more sharply pointed in male than in female. Female genitalia (Fig. 21). Hemisternites well sclerotized and setose near inner apex, with styli elongate, sclerotized, non-setose, and pointed outwards; bursal duct merged into bursa copulatrix; bursa copulatrix without sclerite; accessory gland originated at terminal end of bursa copulatrix; spermathecal duct rather short, arising from a point near the terminal end of bursa copulatrix; spermathecal gland long and slender, not strongly demarcated from its duct; the combined length of spermathecal gland and its duct much greater than the length of the spermatheca.

Diagnosis/Remarks. This new species is similar to Himaloaesalus himalayicus Kurosawa and H. saburoi Araya et al. , but can be distinguished by the following combination of characters: 1) intermandibular projection rounded, not angled; 2) canthus markedly longer; 3) elytra less elongate; 4) abdominal segment 9 of male with shorter basal lobe; 5) basal piece of male genitalia markedly longer; 6) bursal duct merged into bursa copulatrix, not recognizable; 7) spermathecal duct arising from a point markedly closer to the terminal end of bursa copulatrix. This new species can be easily distinguished from Himaloaesalus satoi (Araya and Yoshitomi) and H. zhejiangensis (Huang and Bi) simply by having the scale-like bristles instead of the stick-like bristles on the surface of pronotum and elytra concentrated into clumps. Unlike species of the genus Echinoaesalus Zelenka , the species of the genus Himaloaesalus Huang and Chen have no marked differences from one another in characters of mentum and prosternal process. A study of male and female genitalia is always needed to determine the species in this group.

Distribution. CHINA: Yunnan: Gaoligongshan Mountains.

Etymology. This new species is named after its type locality, a biodiversity hotspot.

Figures

Figures 1–6. Habitus illustrations of Himaloaesalus gaoligongshanus n. sp. under same scale. 1–3) Holotype, male. 4–6) Paratype, female. 1, 4) Dorsal view. 2, 5) Ventral view; 3, 6) Lateral view. Figures 7–8. Head illustrations of Himaloaesalus gaoligongshanus n. sp. in dorsal view. 7) Paratype, male. 8) Paratype female.

Figures 9–14. Characters of Himaloaesalus gaoligongshanus n. sp.. 9–11) Holotype, male. 12–14) Paratype, female. 9, 12) Prosternal process in full face. 10, 13) Mentum. 11, 14) Antenna. Figures 15–20. Male genitalia of Himaloaesalus gaoligongshanus n. sp. taken from holotype under same scale. 15) Abdominal segment 9 in ventral view. 16) Aedeagus in left lateral view. 17) Aedeagus in dorsal view. 18) Aedeagus in right lateral view. 19–20) Aedeagus in ventral view on different ground. Figure 21. Female genitalia of Himaloaesalus gaoligongshanus n. sp. taken from paratype (Fig. 4–6). Abbreviations: mo, median oviduct; bc, bursa copulatrix; sd, spermathecal duct; s, spermatheca; sg, spermathecal gland; ag, accessory gland.