Himaloconnus obesus Yin & Zhou, 2025

Himaloconnus obesus Yin & Zhou , sp. nov.

Chinese common name: Ṁ体喜Ḣẅm

( Fig. 2 View FIGURE 2 )

Type material ( 1 ex.). HOLOTYPE: CHINA: ♂: ‘China: Yunnan, Zhaotong City, Wumengshan Natural Reserve, Xiaocaoba, Miaoshan , 27.846716°N, 104.292419°E, 1830 m, 20.vii.2022, Wei leg., 云南DZdz乌AE山海小¤坝庙 山M国Dzẍ ’ ( SNUC). GoogleMaps

Diagnosis. Male. Body length approximately 1.4 mm. Head dark brown to nearly black, pronotum and elytra reddish-brown. Dorsal surface of body appearing glabrous, almost devoid of setae, thick bristles present on tempora, posterior portion of vertex, and sides of pronotum and humeri of elytra. Antenna slender, antennomeres 1 and 2 each elongate, length 0.09 and 0.08 mm, antennomere 9 and 11 of similar width, 10 broader than 9 and 11, together these three antennomeres form distinct club, antennomeres 3–7 gradually longer. Elytra oval, length/width 1.15. Aedeagus 0.26 mm long, apex of median lobe with acute projection at middle, endophallus armature symmetric, complex in structure; parameres almost reaching apex of median lobe, elongate and slender, each with one long apical and another shorter preapical seta. Female. Unknown.

Description. Male. Body ( Fig. 2A View FIGURE 2 ) length 1.38 mm; head dark brown, pronotum, elytra, antennae and legs reddish-brown, mouthparts and tarsi paler in color. Vertex, sides of head and pronotum and humeri of elytra with long bristles; body dorsum almost impunctate, glabrous, with short and sparse setae found only on disc of elytra.

Head ( Fig. 2A, B View FIGURE 2 ) broadest at eyes, length 0.30 mm, width across eyes 0.28 mm; tempora in dorsal view approximately as long as eyes; vertex and frons confluent, together weakly convex, anterior portion of frons with pair of small, obtuse admesal tubercles; eyes large, strongly prominent laterally, in lateral view suboval, with distinct posteromedian emargination, each eye composed of approximately 20 ommatidia. Vertex with obscure, inconspicuous punctures, almost devoid of setae; tempora and posterior margin of vertex densely covered with long and thick bristles. Submentum with broad and deep central cavity. Hypopharynx with one pair of oval, membranous lateral lobes. Antenna slender, length 0.59 mm, club formed by apical three enlarged antennomeres; antennomeres 1 and 2 each strongly elongate, 3–7 gradually longer, 8 as long as and slightly broader than 7, 9 weakly transverse, 10 more distinctly transverse and much larger than 9, 11 as wide as 9, suboval, club (0.25 mm) less than half of antennal length.

Pronotum roundly triangular, length 0.36 mm, width 0.42 mm, broadest near posterior 1/3, distinctly rapidly narrowing from broadest point toward apex.Anterior margin slightly arcuate, posterior margin indistinctly bisinuate and weakly convex posteriorly at middle, lacking antebasal pits. Pronotal disc almost impunctate, lateral portion with few suberect setae.

Elytra together oval, broadest approximately at middle, length 0.78 mm, width 0.68 mm, length/width 1.15; humeral calli distinct, basal impressions short but well developed; apices separately rounded; disc almost impunctate, glabrous, only center with few scattered short setae. Metathoracic wings fully-developed, long, functional.

Mesoventrite ( Fig. 2C View FIGURE 2 ) with broad intercoxal process; large, transversely oval area surrounding coxae greatly impressed and with setose fringes. Metaventrite with intercoxal process ( Fig. 2D View FIGURE 2 ) formed by pair of acute spines.

Legs moderately long and slender, unmodified; with small plantulae ( Fig. 2E View FIGURE 2 ) between tarsal claws.

Aedeagus (Figs F–I) elongate, length 0.26 mm, dorso-ventrally symmetric; in ventral view broadest in sub-basal region, weakly narrowing distad; apical region broadly subtriangular with blunt apex, with acute apical projection at middle; endophallus armature symmetric and complex, composed of longitudinal tubular component flanked by variously distinct, sclerotized plates of various shapes, in submedian region tubular structure distinctly broadened and forming large vesicle well-visible in lateral view; parameres slender, each with one long apical and one short subapical seta.

Female. Unknown.

Comparative notes. Nine species of Himaloconnus Franz have been described from China (Taiwan), Japan, Thailand, Nepal, and northern India ( Jałoszyński 2020). The aedeagi of most species, where known, exhibit a similar morphology. Only two species, H. shutjensis (Franz) from Nepal and H. klapperichianus (Franz) from Taiwan Island and Japan, have been adequately characterized. Himaloconnus obesus sp. nov. is readily distinguishable from both species by its significantly larger body size, and a bicolored and nearly glabrous dorsal surface of the body. In contrast, H. shutjensis and H. klapperichianus are considerably smaller (≤ 1.0 mm), have uniformly colored bodies, and exhibit evenly distributed setae on the pronotum and elytra. The body size of H. obesus sp. nov. reaches 1.38 mm, making it one of the largest known species within the genus. Among other species, only H. alishanensis (Franz) (1.50 mm) from Taiwan Island and H. ramamensis (1.40 mm) from Nepal have comparative body sizes ( Franz 1979, 1985). The new species can be separated from H. alishanensis by the black head and reddish-brown pronotum and elytra, in contrast to the black head and pronotum and reddish-brown elytra of the latter species. Additionally, H. obesus sp. nov. lacks antebasal pits on the pronotal disc, whereas H. alishanensis possesses six small antebasal pits. From H. ramamensis the new species differs by the bicolored body (uniformly dark reddish-brown in H. ramamensis ), and the lack of antebasal pits on the pronotal disc (with one pair of antebasal pits on the pronotal disc of H. ramamensis ). The remaining species, H. reductipenisides Newton (0.9–0.95 mm), H. nagarkotensis (Franz) (1.05 mm), H. topali (Franz) (0.80–0.90 mm), H. pokharanus (Franz) (0.95 mm), H. hindu (Franz) (0.8 mm), and H. topali (Franz) (0.8 mm), are all much smaller ( Franz 1979, 1981, 1989). Himaloconnus reductipenisides is distributed in Thailand, while the others are found in the Himalayan region.

Distribution. Southwest China: Yunnan.

Etymology. The Latin participle obçsus (- a, - um) means ‘fat, stout’, referring to the stout body form of this species.