Macrotomoderus hengduan, Telnov, 2022

Telnov, Dmitry, 2022, Revision of the Tomoderinae (Coleoptera: Anthicidae). Part III. New species and records of Macrotomoderus Pic, 1901 from China and a key to the Palaearctic species, European Journal of Taxonomy 797, pp. 1-100 : 35-39

Macrotomoderus hengduan sp. nov.

urn:lsid:zoobank.org:act:3C10F9ED-7C43-410B-9E6F-99197F75ABE8

Figs 20–21

Differential diagnosis

This species falls in a group of species from continental China with pronotum wider than head across eyes. Among them, males of M. mirabilis Telnov, 2018 and M. monstrificabilis Telnov, 2018 have distinct triangular median projection at the head base (not present in M. hengduan sp. nov.), while the head base in male M. monstratus Telnov, 2018 is slightly medially impressed (evenly rounded in M. hengduan sp. nov.), the anterior lobe of the pronotum more than twice as long as the posterior lobe (about twice as long in M. hengduan sp. nov.), the front margin of anterior lobe in male with the pointed, triangular mesal projection that is densely setose ventrally and touching the head base at the place of the basal impression (the anterior pronotal projection different in M. hengduan sp. nov. – see Fig. 20B–C , not setose ventrally and with few conspicuous dorsal setae). Also see diagnoses of M. boops and M. dali spp. nov. above and of M. imitator sp. nov. below.

Etymology

Toponymic. Named after Yunnan’s Hengduan Mountains, a group of mountain ranges in southwest China that connect the southeast portions of the Tibetan Plateau with the Yunnan – Guizhou Plateau, where this species occurs. Noun in apposition.

Type material

Holotype CHINA • ♂; “ CHINA, Yunnan, E of Laishkan, 4.5 km ENE of Weixi City, 27°12′03″N 98°20′24″E, 2580 m, 29.v.2016 Kabak & Davidian leg.”; ♂ ZIN [The coordinates on the original label are referring to Myanmar, not Yunnan, but Laishkan and Weixi both are towns in northern Yunnan, not Myanmar].

Paratype (1 specimen) CHINA • 1 ♂; same label as for holotype; DTC .

Description

MEASUREMENTS. Holotype, total body length 4.15 mm; head 0.85 mm long, across eyes 0.8 mm broad, pronotum 1.05 mm long, maximum width 1.15 mm, minimum width 0.35 mm, elytra 2.25 mm long, 1.4 mm combined wide. Paratype is 4.1 mm long.

Dorsum and venter uniformly brown, sutural area of elytra slightly paler. Mouthparts, antennae, palps and legs yellowish-brown. Head elongate ovoid with moderately large, ovoid compound eyes, which are not protruding beyond head outline laterally. Head rounded in broad arc posterior to eyes. Head dorsal punctures minute and inconspicuous. Head dorsal setae inconspicuous, sparse. Antennae conspicuously robust and long, extending towards anterior third of elytra. Antennomere three about 1.3 × as long as antennomere two, antennomeres 8–10 transverse, of them 9–10 strongly transverse. Terminal antennomere asymmetrically triangular with rounded apex, twice as long as penultimate antennomere. Terminal maxillary palpomere securiform. Pronotum with anterior lobe significantly wider than posterior and wider than head across eyes. Postmedian lateral constriction broad and medially shortly notched. Front margin of anterior lobe subtruncate, dorsally with narrow anterior rim. Anterior lobe large and broad, inverted triangular; posterior lobe shorter and much narrower. Front margin of anterior lobe with short, median, anteriad-directed projection and shallow antero-dorsal impression posterior to it; projection is dorsally provided with two erect (straight) and two ך-shaped (bent), anteriad-directed setae ( Fig. 20B–C ). Anterior and posterior lobe convex in lateral view ( Fig. 20C ). Lateral constriction continues onto disc in lateral view, shallow ( Fig. 20C ). Lateral pronotal fovea broad and deep at lower external margin of pronotum, strongly widens upwards towards pronotal disc in lateral view, external margins protruding into a pair of obtuse (in lateral view), widely separated denticles (in lateral view), which are provided with long, sparse setae. Cavity in lateral wall of pronotum between lateral denticles large, elliptical. In dorsal view, lateral pronotal fovea narrow, anterior and posterior pair of denticles appear obtusely angulate, glabrous ( Fig. 20B ). Pronotal punctures minute on disc; lateral constriction dorsally with sparse, rather small punctures. Dorsal pronotal setae inconspicuous, moderately long. Scutellar shield minute, triangular. Elytra dorsally elliptical, slightly convex in lateral view, widened laterally around midlength, lateral margins evenly broadly rounded, shoulders obsolete (apterous species). Elytral punctures rather small and moderately dense, becoming slightly smaller and sparser towards apices. Elytral setae long and sparse, suberect. Male tergite and morphological sternite VII broadly rounded at posterior margin. Aedeagus as in Fig. 21 , large and dagger-shaped, with short, spherical basale and inconspicuous, delicate, irregularly filamentous gonopore armature.

Sexual dimorphism

Female is unknown.

Ecology

Collected at 2580 m elevation.

Distribution

Known only from Hengduan Mountains, northern part of Yunnan Province, SW China.

Figures

Fig. 20. Macrotomoderus hengduan sp. nov., holotype, ♂ (ZIN). A. Habitus, dorsal view. B. Forebody, dorsal view. C. Ditto, lateral view. Scale bar: A = 1 mm; B–C = not to scale.

Fig. 21. Macrotomoderus hengduan sp. nov., holotype, ♂ (ZIN), aedeagus. A–B. General view, different positions. C. Gonopore armature, median portion of apicale. D. Ditto, apical portion of apicale. E. Basal portion of apicale. F. Ditto, stronger magnification. Not to scale.