Nebria (Epinebriola) delicata Huber & Schmidt, 2017, sp. nov.
Creators: name: Huber, Charles
name: Schmidt, Joachim
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Nebria
Nebria delicata

description: Nebria (Epinebriola) delicata sp. nov. (Fig. 30)
Holotype ♂: S Tibet, Mt. Mendju Zari, SE Lhasa, 29°34' N, 91°13' E, 5200– 5420 m, 4.6.2011, leg. J. Schmidt (cSCHM).
Paratype: 1 ♀, same data as holotype (cSCHM).
Body length 9 mm. Colour dark brown to black. Appendages of the head, antennae, tibiae and tarsi brownish lightened.
Head small. Labrum with anterior margin straight, bearing eight setae. Clypeus with anterior margin straight. Frons transversally wrinkled. Eyes small, weakly prominent, temples long. One supraorbital seta. Head with a faint collar constriction. Vertex impunctate. Antennae long and slender extending at least to the middle of the elytra. Antennal scape slender, elongate, cylindrical, longer than the eye's diameter, basally narrowed, with one dorsal seta. 2 nd antennomere with one seta ventroapically. Maxillar palpomeres short. Maxillary stipes laterally straight, with 5 setae. Penultimate labial palpomere trisetose. Ligula spiny, with two lateral setae. Mentum with bifid medial tooth. Submentum with a row of 4+5 setae. Vertex impunctate. Microreticulation of the head isodiametric.
Pronotum slender, ratio width/length of the pronotum = 1.25. Lateral margin faintly convex, slightly narrowed basally (ratio apical width/basal width = 1.07), rounded to the anterior angles, faintly rounded to the posterior angles, weakly concave in front of the posterior angles (Fig. 31H). Lateral groove very narrow, narrow evenly apically, broadened basally. Anterior angles faintly acuminate, slightly protruding. Posterior angles acute, slightly protruding backwards. Basal margin medially straight, in front of the posterior angles weakly sinuate. Pronotal disc weakly convex. Basal fovea deep, anterior transverse impression weak, posterior transverse impression distinct, median line shallow. Lateral groove and anterior transverse impression impunctate; basal fovea and posterior transverse impression sparsely punctate. Apical margination of the pronotum restricted to lateral one-fourths, merges with the apex of the anterior angle. Base of the pronotum not margined. Basolateral seta present. One midlateral seta in the apical half of the pronotum, inserted within the narrow lateral groove; outline of the lateral margin at the insertion site of the seta weakly disturbed. Pronotum impunctate on disc, microreticulation isodiametric. Proepisternum smooth. Prosternal process laterally margined, apex bulging and unmargined.
Elytral silhouette slender, elongate, convex with the lateral margin almost straight in the middle, widest slightly behind the middle. Ratio length/width of the elytra = 1.71. Distinctly wider than the pronotum, ratio elytral width/pronotal width = 1.65. Elytral apex acutely rounded, apical carina faint. Basal margination straight, at right angles with the elytral suture, regularly merged with the lateral margination. Humeral carina weakly present. Striae distinct, deep, reaching the apex, striae 1–2 faintly punctate, the remaining striae coarsely punctate; lateral striae obliterate towards the apex. Intervals slightly convex. Interval 3 with 2–4 setae adjoining stria 3, intervals 5 and 7 asetose. Scutellar seta absent. Microreticulation isodiametric, interspersed with transverse meshes. Mesepisterna sparsely punctate.
Sternum 2 laterally faintly punctate. Sternum 3 medially asetose. Sterna 4–6 posteriorly each with 1–3 paramedial setae; anal sternum with two paramedial setae in the male. Metepisterna twice as long as wide, sparsely punctate. Metacoxa basally bisetose, apically unisetose.
Legs long and slender. Tarsi slender, tarsomeres 1 and 2 dorsally with a few short setae. Protarsus of the male with tarsomeres 1–3 broadened, ventrally with pads of adhesive setae. Ventroapical tooth of the metatarsomere 4 small and only little projecting. Meso- and metatarsomeres 2–4 ventroapically with long setae. Tarsomeres 5 ventrally with two rows of 3–4 short setae. Metatarsomere 5 as long as metatarsomeres 3+4.
Male genitalia: Edeagus (Fig. 20G): Base of the median lobe small, with small basolateral lobes; the base decreasing abruptly to the thin mid-shaft. Mid-shaft strongly curved at base on inner side as well as on outer side; moderately curved to the apex. Apex straight, faintly deflected to the left, in front of the long tip on the ventral side faintly convex. Mid-shaft of the endophallus asetose.
Female genitalia: Gonocoxa (Fig. 32): Gonocoxite 2 very long, as long or longer than gonocoxite 1, slender, curved dagger-like, broad at base, distinctly narrowing near base, parallel sided in median part. Apex acuminate, slightly arcuate dorsally. Ventral preapical insertion furrow small, short-oval, with two nematiform setae.
Body ratios: hea.w/fro.w = 1.38; prm.w/hea.w = 1.16; prm.w/prp.w = 1.47; pra.w/prp.w = 1.07; ely.w/prm.w = 1.71; prm.w/prm.l = 1.21; ely.l/ely.w = 1.69.
Etymology: The specific epithet refers to the habitus and to the finely margined pronotum (delicatus, latin = delicate, dainty, fine).
Diagnosis: N. delicata sp. nov. is recognizable within the subgenus Epinebriola by its dainty habitus and by the anterior margin of the labrum with a row of eight setae instead of six. A labrum of eight setae is also present in N. pindarica – distributed in Uttarakhand, India –, a large species of 13–15 mm with the lateral margin of the pronotum distinctly concavely narrowed in front of the posterior angle and with hanging shoulders, whereas in the small (9 mm) species N. delicata sp. nov. the lateral margin of the pronotum is only faintly concave in front of the posterior angle, and the shoulders are pronounced. N. delicata sp. nov. is closely related to N. retingensis sp. nov. due to the resemblance in the shape of the median lobes (Figs 20F, 20H).
Remark: Generally the species of the genus Nebria have the anterior margin of the labrum with a row of six apical setae with the exception of N. (Epinebriola) pindarica, N. (Tyrrhenia) eugeniae K. Daniel, 1910, and N. (Alpaeonebria) exul Peyerimhoff, 1910 which all have eight setae, and of N. (Eonebria) lucifer Ledoux & Roux, 1998 with ten setae (Ledoux & Roux 2005). Obviously the evolution to eight or more labral setae happened convergently several times in different subgenera within the genus Nebria.
Distribution (Fig. 41): Known only from the type locality, the Mendju Zari Mountain SE of the Lhasa Valley in the central Transhimalaya (Gangdise Shan).
Habitat (Fig. 33): Both specimens of the type series were collected on a humid slope in the high alpine zone.
Remark (see Fig. 34): The gonocoxites 2 of N. (Epinebriola) retingensis sp. nov. (Fig. 10J, 34A) and N. (Epinebriola) delicata sp. nov. (Fig. 32) are conspicuous in length and shape. Such long and dagger-shaped gonocoxites 2 are neither described nor mentioned in relevant Nebria literature (Ledoux & Roux 2005). In the present case the gonocoxite 2 of N. retingensis sp. nov. (Fig. 34A) is compared with those of some species of the subgenus Eonebria SEMENOV & ZNOJKO, 1928. The gonocoxites 2 of N. (Eonebria) kurentzovi LAFER, 1989 (Anisimovka, Primorsk. Kr. Litovka, Far East Russia; coll. NMBE. Fig. 34B) and of N. (Eonebria) gemina LEDOUx, ROUx & WRASE, 1996 (Qin Ling Shan, Tabai Shan, Shaanxi, China; coll. NMBE. Fig. 27C) look similar to that of N. (Epinebriola) retingensis sp. nov., whereas in N. (Eonebria) amabilis LEDOUx, ROUx & SAWADA, 1991 (Heka, Qinghai, China; coll. NMBE. Fig. 34D) the gonocoxite 2 is shaped in a rather "normal", not dagger-like way. The subgenus Eonebria currently consists of 74 taxa, and the selected three taxa may not be representative for the whole subgenus. But the gonocoxites 2 of the selected Eonebria species may point to a certain variability of the gonocoxite shape as in the subgenus Epinebriola. A re-evaluation of the subgenus Eonebria including the disregarded gonocoxal characters may be required, but such an analysis was not the objective of the present study. For now we leave N. retingensis sp. nov. and N. delicata sp. nov. within the subgenus Epinebriola, and we interpret the dagger-like gonocoxite 2 as being convergent to those of some Eonebria species.
description: Published as part of Huber, Charles & Schmidt, Joachim, 2017, Notes on the Nebria subgenus Epinebriola K. DANIEL, 1904 with the description of Barbonebriola subgen. nov. and 13 new species from the Himalaya-Tibet orogen (Coleoptera, Carabidae, Nebriini), pp. 1-85 in Contributions to Natural History 36 on pages 59-64, DOI: 10.5169/seals-787049, http://zenodo.org/record/6285683