Brachyllus tangzhaoyangi Zhao, 2023

Zhao, Ming-Zhi, Qi, Zhi-Hao, Su, Rong-Xiang & Liao, Tao-Kun, 2023, New and poorly known species of the genus Brachyllus Brenske, 1896 (Coleoptera Scarabaeidae: Melolonthinae) from China, Zootaxa 5256 (4), pp. 358-370 : 364-366

Brachyllus tangzhaoyangi Zhao , new species

( Figs. 5 , 7O–P )

Type material. Holotype ♁ ( SCAU), “ CHINA: Guangxi, Chongzuo, / Longzhou, Binqiao Township , / Raoxiucun Village [ṀŘLj], Nadongtun [AEẆ‡], / Mt. Daqingshan N. R., V – VI.2022 / Yu Nong leg.”

Description of the holotype ( Figs. 5 , 7O–P ). Elongated ovoid, subcylindrical, somewhat broadened behind.

Colour. Dorsal surface black, with strong coppery luster. Ventral surface dark brown, tibiae, tarsi and anterior portions of clypeus as well as mesosternum reddish brown. Antennae and setae yellowish brown.

Head. Clypeus strongly emarginated, anterior margin reflexed, lateral corner rounded, lateral margin somewhat subparallel. Frontoclypeal suture distinct, weakly raised at middle. Inner margin of eyes weakly raised. Surface of clypeus and frons with dense and large punctures, vertex impunctate. Each puncture with a moderately long and erect seta; some punctures on posterior half of frons each with an ovate scaly seta. Antenna 9-segemented, antennal club 3-segmented, length of antennal club equals to the combined length of antennomeres 3–5, antennomere 2 glabrous.

Pronotum. Wider than long. Lateral margin parabolic in posterior five sixth, straight in anterior sixth, with scalloped modification. Anterior angle strongly protruding and acute at apex, posterior angle obsolete, surface depressed on all margins except before the scutellum. Surface with dense and large punctures, punctures slightly more aggregated near lateral portions. Each puncture with an ovate scaly seta, some of them being larger at lateral portions, or also being oval along posterior margin; lateral margin of pronotum along with several long setae.

Scutellum. Subtriangular, apex rounded, margins weakly arched. With dense punctures somewhat smaller than those on disc of pronotum, lateral portions impunctate. Each puncture with a scaly seta.

Elytra. Surface without any reliefs, the sutural interval indistinctly defined, other intervals hardly recognizable; humeral and subapical umbones moderately prominent. Surface with moderately dense large punctures, punctures as large as those on pronotum. Each puncture with a lance-shaped or oblanceolate scaly seta, half of them are as large as those on pronotum, mixed with some much larger and oval scaly setae, distinctly aggregated before subapical umbone; lateral margin with several rather short setae, epipleura with a row of short setae.

Ventral thoracic surface. Ventral prothoracic surface with dense large punctures, ventral meso- and metathoracic surfaces with slightly smaller but denser punctures. Ventral prothoracic surface and mesoventrite with dense and long setae, which becoming rather longer on metaventrite, mesoventrite glabrous anteromedially. Prosternal process small and conical, not extending beyond procoxa.

Abdomen. Abdominal ventrites I–V weakly carinate laterally. Abdominal ventrites with moderately dense punctures, becoming denser laterally, the punctures are as large as those on metaventrite; ventrite VI with punctures on posterior half only. Each puncture with a moderately long seta, each puncture on lateral portions of each ventrite with a large and lanceolate scaly seta, the scaly setae are more elongated on ventrite V, ventrite VI with a row of moderately dense setae along posterior margin. Pygidium weakly convex, surface with dense and large punctures; each puncture with a large and oblanceolate scaly seta, posterior margin a row of long setae.

Legs. Slender. Protibia tridentate, apical and second teeth prominent, proximal tooth small but acute, equally spaced; without protibial spur. Each tarsal claw (except for the missing metatarsal claw) with a strong medial tooth. Femora with moderately dense large punctures. Meso- and metafemora with irregularly distributed and rather long setae, profemora with moderately long setae; tibiae with short setae at outer surface.

Male genitalia. As in Fig. 7O–P .

Female. Unknown.

Measurements. Body length (measured from anterior margin of clypeus to apex of elytron): 12.2 mm, body width (measured across humeri): 5.3 mm.

Differential diagnosis. Brachyllus tangzhaoyangi Zhao , new species appears to be the most peculiar Brachyllus species. It is easily recognized by its elytra without any reliefs, dorsal surface strongly coppery in combination to numerous distinct scaly setae. Those traits are not shared by any other congeners. However, other structures, e.g. antenna, pronotum and legs, clearly subject its status to Brachyllus .

Etymology. This species is dedicated to Zhao-Yang Tang, who donated the holotype of the new species.

Figures

FIGURE 5. Habitus of Brachyllus tangzhaoyangi new species, holotype. A, dorsal view; B, ventral view.

FIGURE 7. Male genitalia of Brachyllus species. A–B, B. songhaitiani new species, holotype; C–D, B. deuveianus, holotype; E–F, B. rougeriei rougeriei, holotype; G–H, B. rougeriei langeri; I–J, B. dongzhiweii new species, holotype; K–L, B. frontalis; M–N, B. itohi mantilleri, holotype; O–P, B. tangzhaoyangi new species, holotype. Upper row, parameres in dorsal view; lower row, aedeagus in lateral view.