Achaetomalachius nyingchiensis Yang & Miao, 2025

Miao, Jialin, Liu, Haoyu, Tong, Junbo, Yang, Xingke & Yang, Yuxia, 2025, A new species of Achaetomalachius Majer, 1989 (Coleoptera, Dasytidae) from Xizang, China, Zootaxa 5665 (1), pp. 111-120 : 113-116

publication ID	https://doi.org/10.11646/zootaxa.5665.1.7
publication LSID	lsid:zoobank.org:pub:8803ED84-60AD-44ED-9295-CED97C45990A
persistent identifier	https://treatment.plazi.org/id/03A187E0-7D35-FFAC-E2C2-FF08FB2F73DB
treatment provided by	Plazi
scientific name	Achaetomalachius nyingchiensis Yang & Miao
status	sp. nov.

Treatment

Achaetomalachius nyingchiensis Yang & Miao , sp. nov.

( Figs 1‒4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Diagnosis. This species can be easily distinguished from all other species of Achaetomalachius by the shape of tegmen and median lobe of aedeagus. It looks similar to A. tibetensis ( Champion, 1925) , but can be distinguished by the combination of following characters: femora black, tibiae and tarsomeres orange and more or less darkened at apices; pronotum with nearly straight posterior margin in males ( Fig. 2A View FIGURE 2 ); tegmen strongly bent ventrally at base ( Fig. 3C, E View FIGURE 3 ); apical limb of median lobe stout, 4.5 times longer than basal width, with apex slightly incurved ventrally in lateral view ( Fig. 3G View FIGURE 3 ). Unlike in A. tibetensis , legs testaceous, femora and pretarsi more or less darkened at base and/or apex; pronotum with arcuate posterior margin in males ( Majer 1996a: fig. 1); tegmen slightly bent ventrally at base ( Majer 1996a: fig. 26); apical limb of median lobe slender, 8.0 times longer than basal width, with apex directing apically and nearly straight ventrally in lateral view ( Majer 1996a: fig. 46).

Description. Male. ( Fig. 2A View FIGURE 2 ). Body length 3.8‒4.1 mm (4.1 mm in holotype), width 1.1‒1.3 mm (1.3 mm in holotype).

Body black with dark green metallic lustre. Antennae black, except for antennomeres 2‒5 orange, 4‒5 more or less darkened. Ultimate maxillary and labial palpomeres brown and darkened at apices. Femora black, tibiae and tarsomeres orange and more or less darkened at apices. Body surface densely and shallowly punctate, densely covered with short and recumbent pale pubescence, and a few long and erect black setae.

Eyes distinctly prominent, head width across eyes obviously wider than anterior margin of pronotum. Antennae extending to basal 1/7 length of elytra when inclined, antennomeres 1 nearly conical, 2‒3 ellipsoidal, 4‒7 triangular and longer than wide, 8‒10 nearly globular, 11 fusiform, 2.3 times as long as wide.

Pronotum transverse and 1.2–1.3 times as wide as long, widest near basal 2/5, anterior and posterior margins nearly straight, lateral margins arcuate with sparse crenation, anterior and posterior angles widely rounded. Elytra subparallel-sided, 2.0–2.1 times longer than humeral width, 2.5–2.6 times longer than pronotum, broadly rounded at apices. Femora stout, tibiae slender, metatibiae feebly curved inwards at apex.

Ultimate abdominal ventrite ( Fig. 3A View FIGURE 3 ) strongly transverse and bipartite, with antero-lateral angles acute, surface covered with a few long curly black setae and some short erect setae near middle of posterior margin. Pygidium ( Fig. 3B View FIGURE 3 ) slightly transverse, 1.2 times wider than long, feebly narrowed posteriorly, nearly straight at anterior margin, hardly emarginate in middle of posterior margin, with antero-lateral angles protruding and acute at apices, which are directed posteriorly, surface covered with a few long curly setae and some short erect setae along lateral and posterior margins. Spiculum gastrale ( Fig. 3H View FIGURE 3 ) with basal trunk shorter than apical branch.

Aedeagus: Tegmen in ventral view slightly dilated at basal part, with submedian dilation distinctly angled, the subapical ring reaching basal 2/5 ( Fig. 3C View FIGURE 3 ); tegmen in lateral view strongly bent ventrally at basal third, the bent part with a median line on inner surface ( Fig. 3E View FIGURE 3 ). Median lobe in lateral view with basal limb approximately rectangular, apical limb 4.5 times longer than basal width, gradually tapering apex which is slightly incurved ventrally ( Fig. 3G View FIGURE 3 ).

Female. ( Fig. 2B View FIGURE 2 ). Similar to male, but body stouter, 4.1–4.2 mm in length, 1.3–1.4 mm in width.Antennomeres 2–3 orange and more or less darkened. Eyes moderately prominent, head width across eyes feebly wider than anterior margin of pronotum. Antennae slightly shorter, extending to posterior margin of pronotum when inclined. Elytra feebly dilated posteriorly. Metatibiae straight. Ultimate abdominal ventrite ( Fig. 4A View FIGURE 4 ) bipartite, each lobe slightly narrowed laterally, about 3.0 times as long as wide, with antero-lateral angles acute, the median process very slender and distinctly extending beyond antero-lateral angles. Pygidium ( Fig. 4B View FIGURE 4 ) nearly straight at anterior margin, large and triangularly emarginate in middle of posterior margin, with antero-lateral angles obviously protruding and acute at apices, which are directed laterally.

Type material. Holotype: China: Xizang: ♂ ( IZAS), Nyingchi City , 3050 m, 05.VIII.1983, collector unknown.

Paratypes: China: Xizang: 4♂♂ 3♀♀ ( IZAS), same data as the holotype. Distribution ( Fig. 1 View FIGURE 1 ). China (Xizang). Etymology. The species epithet is derived from the name of the type locality, Nyingchi City, Xizang Autonomous

Region, China.

Remarks. The species of Achaetomalachius are predominantly found in the central and western Himalayan area, with the type locality of this new species being the easternmost point within its distribution range. This discovery suggests that it is reasonable to uncover more species in the eastern Himalayas in the future.