Macrotomoderus nanling, Zhao & Wang, 2025

Zhao, Yuchen & Wang, Xinpu, 2025, New species of Macrotomoderus Pic (Coleoptera: Anthicidae) from Southern China, Zootaxa 5660 (3), pp. 389-402 : 396-397

Macrotomoderus nanling sp. nov. (南ẇ大OiṚDzş)

Figures. 39–46

Type material designated: Holotype: ♂, Nanling (南ĸ), Ruyuan Yao Autonomous County (乳DZNJânā县), Shaoguan City (ȇẍǖ), Guangdong Province (Ḟ东å), China, 01-VI-2021, GPS. 113.0243E, 24.8928N, alt. 1400 m ( SANXU).

Measurements. Holotype. Total length 3.75 mm; head length 0.83 mm, head width across compound eyes 0.79 mm; pronotum length 1.01 mm, maximum pronotal width 0.66 mm, minimum pronotal width 2.93 mm, elytra length 1.88 mm, combined maximum elytral width 1.29 mm.

Description. Head, pronotum, and elytra uniformly brown; antennae, maxillary palps and legs comparatively slightly lighter.

Head broadly subpentagonal, moderately glossy dorsally and ventrally; eyes medium-small with black border, not protruding beyond lateral or dorsal outline of head; Tempora longer than eye length, slightly narrowing towards head base, posterior temporal angle broadly rounded; head base slightly truncate in dorsal view; punctures on head minute, with intervening spaces glossy and glabrous, much wider than punctures, several larger varying sizes punctures scattered on vertex; setae on head whitish to yellowish, distinct, subdecumbent, and directed toward the middle of head base; few longer, erect tactile setae scattered on lateral sides of head; antennomere III longer than antennomere II and than antennomere IV; antenomeres II, VI and V with similar length antenomeres V to X gradually widen, while antennomeres VII to X are distinctly transverse; terminal antennomere broadly hemispheric with rounded apex, about 1.5 times as long as penultimate antennomere; Terminal maxillary palpomere broadly triangular to securiform.

Pronotum (fig. 40) slender, length greater than width, moderately glossy dorsally and laterally, with broad and medially shallowly notched postmedian lateral constriction; front margin of anterior lobe broadly rounded, without anterior rim; in dorsal view, lateral pronotal fovea wide, anterior denticles and posterior denticles appearing rightto acute-angled (fig. 40a); in lateral view, anterior lobe slightly convex, lateral constriction not continues onto disc, lateral pronotal fovea moderately broad with distinct margin of pronotum, widens upwards towards pronotal disc, without distinct denticle at anterior and posterior margins of fovea, only slightly thickened; without specialized setae on the fovea (fig. 40b); pronotal dorsal punctures generally similar to those on head, intervening spaces moderately glossy; constriction area dorsally with dense, large, irregularly circular punctures, separated by much less than puncture diameters; lateral margins of pronotum minutely punctured; pronotal setae yellowish, dense, subdecumbent; with few longer erect tactile setae present on lateral sides of anterior lobe.

Scutellar shield minute, slightly rounded apically.

Elytra dorsally elliptical, slightly flattened in lateral view, widened laterally around midlength, lateral margins evenly broadly rounded, moderately glossy. humeral angle with minute beak-shaped nodular, apterous species; punctures circular, much stronger and larger than those on dorsal forebody, smaller and less coarse than dorsal punctures on pronotal constriction; a row of slightly larger, irregularly arranged punctures on each side of the elytral suture; setae yellowish, rather long and dense, suberect.

Each tibia with basal half flattened, fore tibia with weakly blunt angulate expansion near middle on inner side, hind tibia inner edge slightly curved at basal third.

Male tergite VII broadly rounded at posterior margin, sternite VII shallowly excavated on apical margin; sternite VIII, spiculum gastrale and aedeagus as in figures 45 and 46.

Diagnosis. This species superficially resembles the M. gracilicollis species group ( Telnov, 2007) in its slender pronotum, specialized elytral humeral angle, and tibial morphology. Although these similarities suggest potential affinity, the taxonomic placement within this group is provisionally withheld pending further study. This species can be distinguished from members of M. gracilicollis species group by the combination of characteristics: the slightly outwardly curved outer margin of the fore tibia, the absence of a central longitudinal ridge on the pronotum, and a body length greater than 3.0 mm; and it can be clearly differentiated from other species by aedeagus morphology. The pronotal shape of this species is similar to that of M. angelinii Telnov, 2022 ( China: Yunnan), but distinct differences are evident in pronotal punctation and elytral length. In comparison with M. insolitus sp. nov., M. nanling sp. nov. with distinctly slender pronotum, smaller extensions of foretibia, relatively smaller compound eyes, and smaller humeral angle nodular.

Etymology. This species is named after the Nanling Mountains, the largest mountains range in southern China, which marks the boundary between temperate and subtropical zones, where this species was first collected. Noun in apposition.

Distribution. China (Guangdong).

Figures

FIGURES 39–46. Macrotomoderus nanling sp. nov., holotype. (39) habitus of male; (40) Pronotum, (a) dosal view, (b) lateral view; (41) sternite VII, ventral view; (42) tergite VII, dorsal view; (43) sternite VIII, ventral view; (44) tergite VIII, dorsal view; (45) spiculum; (46) aedeagus, (a) ventral view, (b) lateral view. Scale bar: 1 mm for fig. 39; 0.5 mm for figs. 41–56.