Macrotomoderus transitans, 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 : 66-68

Macrotomoderus transitans sp. nov.

urn:lsid:zoobank.org:act:D09B8E41-E71A-49A3-BE31-905D3F6E4C42

Figs 38–39

Differential diagnosis

This species appears similar to the Indo-Chinese congeners with anteriorly excavate and medially longitudinally carinate pronotum, like Macrotomoderus humerifer (Uhmann, 1994) (N Vietnam), M. perforatus Telnov, 2019 ( China: Yunnan), and M. yunnanus ( Telnov, 1998) ( China: Yunnan). The new species has obsolete humeri (humeri angulate in M. humerifer , this species is macropterous) and the anterior pronotal impression without peculiar, high frontal wall and peculiar, thick golden setae as in M. yunnanus . In M. perforatus the aedeagus is rather similar to that of M. transitans sp. nov., but the head is rounded at the base and delicately punctured (the head base subtruncate, the head dorsal punctures are conspicuous, large), the pronotum is generally slenderer and the anterior emargination – larger and deeper than in M. transitans sp. nov., the compound eyes comparatively smaller than those of M. transitans sp. nov. and the antennal club is less heavy.

Etymology

Named from the Latin ‘transitans’ (‘passing through’) to point on the area of occurrence of this species that might be transitional to Oriental fauna.

Type material

Holotype CHINA • ♂; “CHINA, YUNNAN Prov. 8 km NW Gudong, Yunteng Shan Nat. Park , 25°22.70N, 98°24.38E, J. Hájek & J. J. Růžička leg. // (Ch19) 29.v.2018, 1850 m, sift #15, secondary broad-leaved forest with shrubs, above lower cable car station ”; NMP.

Description

MEASUREMENTS. Holotype, total body length 3.96 mm; head 0.8 mm long, across eyes 0.8 mm broad, pronotum 0.95 mm long, maximum width 0.75 mm, minimum width 0.2 mm, elytra 2.2 mm long, 1.65 mm combined wide.

Dorsum and venter uniformly brown to reddish-brown. Mouthparts, antennae, palps and legs yellowishbrown. Head subtriangular with moderately large, ovoid compound eyes, which are slightly protruding beyond head outline laterally. Tempora converging towards head base (slightly rounded), temporal angles broadly rounded. Head base subtruncate in dorsal view; in posterodorsal view head base appears truncate at least medially since occiput is somewhat flattened posteroventrally above insertion of cranial neck. Head dorsal punctures small but distinct, rather deep, moderately dense. Intervening spaces glossy and glabrous, about same size as to 3 × as large as punctures. Head dorsal setae moderately dense. Antennae barely touching base of pronotum. Antennomere three nearly same length as antennomere two, antennomeres 4–5 shortened, ovoid, antennomeres 6–10 transverse, of them 9–10 strongly transverse. Terminal antennomere short and broadly triangular with rounded apex, about 1.7–1.8× as long as penultimate antennomere. Terminal maxillary palpomere securiform. Pronotum with broad and medially deeply and broadly notched postmedian lateral constriction. Front margin of anterior lobe very broadly rounded (subtruncate), in male moderately deeply and broadly impressed mesally opposite median part of head base; anterolateral margins of this impression raised in dorsal aspect, produced into acute denticles ( Fig. 38B ). Anterior edge of pronotum in male in front of anterior impression with thick, rather low median wall that is provided with 2–4 stout, erect setae. Pronotum dorsally without anterior rim. Anterior lobe slightly convex in lateral view ( Fig. 38C ). Lateral constriction continues onto disc in lateral view, shallow ( Fig. 38C ). Lateral pronotal fovea broad 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). Cavity in lateral wall of pronotum between lateral denticles not observed since the area laterally concealed by dense, whitish setae. In dorsal view, lateral pronotal fovea broad, anterior and posterior pair of denticles appear obtusely angulate, glabrous laterally ( Fig. 38B ), each with a bunch of dense, golden dorsal setae. Anterior lobe gently medially longitudinally carinate all along. Pronotal punctures minute on disc; lateral constriction dorsally dense and coarse, irregularly punctured. Dorsal pronotal setae inconspicuous. Scutellar shield very small, apically rounded. Elytra dorsally elongate elliptical, convex in lateral view, widened laterally around midlength and broadly rounded at lateral margins, shoulders obsolete (apterous species). Elytral punctures moderately large and deep, moderately dense on basal half of elytra, becoming smaller and shallower towards apices. Intervening spaces on basal half of elytra about 2–3× as large as punctures. Elytral setae long and rather dense, suberect. Male tergite and morphological sternite VII broadly rounded at posterior margin. Aedeagus as in Fig. 39 , large and robust, basale arch-shaped. Gonopore armature ‘garland’-like, with consisting pieces very densely attached to one another, moderately large, spinose.

Sexual dimorphism

Female is unknown.

Ecology

Collected from leaf litter in a secondary broad-leaved forest at 1850 m elevation.

Distribution

Known only from western part of Yunnan Province, SW China.

Figures

Fig. 38. Macrotomoderus transitans sp. nov., holotype, ♂ (NMP). A. Habitus, dorsal view. B. Forebody, dorsal view. C. Ditto, lateral view. Scale bar: A = 1 mm; B–C = not to scale.

Fig. 39. Macrotomoderus transitans sp. nov., holotype, ♂ (NMP), aedeagus. A–B. General view, different positions. C. Gonopore armature, apical portion of apicale. D. Ditto, basale and basal portion of apicale. E. Ditto, different position. F. Median portion of basale. G. Apical portion. Not to scale.