Asialassus, Nabozhenko, Maxim & Ando, Kiyoshi, 2018

Nabozhenko, Maxim & Ando, Kiyoshi, 2018, Subtribal, Generic And Subgeneric Composition Of Darkling Beetles Of The Tribe Helopini (Coleoptera: Tenebrionidae) In The Eastern Palaearctic Region, Acta Zoologica Academiae Scientiarum Hungaricae 64 (4), pp. 277-327 : 311-312

Asialassus gen. n.

(Figs 17–26)

Type species: Helops cordicollis Marseul, 1876

Diagnosis. Male. Body slender, shiny, brown, sometimes with metallic glance. Eyes large, convex. Head with or without posterior grooves beginning at lower aspect of eyes. Male antennae constantly thin, antennomeres not more thickened than in female. Anterior margin of frontoclypeus straight. Pronotum large, usually moderately convex. Prothoracic hypomera with longitudinal or irregular wrinkles. Prosternum clearly flattened, with distinct transverse wrinkles before procoxae ( Figs 18B, D , 19C , 20B , 21F, G , 22C , 23B , 24F , 25C , 26E ). Prosternal process with large acute teeth laterally, depressed at middle, strongly projected apically ( Figs 18C , 20C, D , 21F, G , 22C, D , 23C , 24F, H , 25B, C , 26E, F ). Elytra without humeral calli, with clear striae, punctures in striae connected with each other. Interstriae without tubercles, but with simple coeloconic sensilla. Eighth interstria apically more convex than the rest, connected with elytral margin. Dorsal epipleural carina reaching eighth interval at apex. Elytral epipleura not reaching elytral apex and terminate at level of 4th and 5th abdominal ventrites. Hind wings developed (the ability to fly is unknown to us). Mesoventrite slightly depressed at middle. Metaventrite transverse, glabrous. Abdominal ventrites without hair brushes. Male protibiae curved, ladle-shape, widened and flattened apically, often with one or two teeth before apex ( Figs 18G , 19B , 21C, D , 22E, F , 24B, C , 25D, E , 26B, C ); mesotibiae sometimes with line of large ( Fig. 18H ) or small granules ( Figs 22H , 25F ) on ventral side. Male tarsi not widened. Trochanters with single long seta.

Aedeagus ‘nalassoid’, weakly sclerotized, apical piece with flattened keel at apex (Figs 17A–O).

Female. Body robuster than male, antennae shorter. Prosternal process simple, without teeth ( Figs 18E , 19C ). Tibiae not modified ( Fig. 19B ). Procoxae with elevated portion near trochanters, prostenal process depressed at middle between procoxae ( Fig. 18F ). Genital tubes (Fig. 17P). Spermatheca consists of only one non-branched tube, with clear basal duct. Accessory gland short, a little longer than spermatheca or subequal to spermathecal length.

Comparison. The genus differs from all known Helopini in the structure of toothed and depressed male prosternal process, transverse wrinkles of flattened prosternum before procoxae and elevated outer sides of female procoxae. Asialassus gen. n. is the most close to the genus Nalassus . See differeces between these two genera in the key above.

Composition. The new genus contains six species from Japan and Korean Peninsula.

Etymology. The name derives from compound word of “Asia” and generic name “ Nalassus ”.

Gender. Masculine.

Figures

Fig. 18. Asialassus cordicollis, details of structure: A = head, ventral view, B = male prosternum, C = male prosternal process, D = female prothorax and fore legs, ventral view, E = female prosternal process, ventral view, F = female prothorax, posterior transverse view (lateral arrows show elevate margin of procoxae, middle arrow shows depressed prosternal process between procoxae), G = male protibia, H = male mesotibia

Fig. 19. Asialassus amamiensis, holotype, female: A = habitus, B = protibia, C = prothorax, ventral view, D = labels of the holotype

Fig. 20. Asialassus amamiensis, male, details of structure: A = head, B = prosternum, C = prosternal process, ventral view, D = prosternal process, lateral view

Fig. 21. Asialassus kimurai, holotype and paratype: A = holotype, male, habitus, B = paratype, female, habitus, C = male protibia, dorsally, D = male protibia, ventrally, E = male mesotibia, F = male prothorax ventro-laterally, G = male prothorax, ventrally, H = aedea-

Fig. 22. Asialassus kimurai, holotype and paratype of the new junior synonym Tarpela tokunoshimana: A = holotype, male, habitus, B = paratype, female, habitus, C = male prothorax, ventrally, D = male prothorax, laterally, E = male protibia, dorsally, F = male protibia, ventrally, G = male mesotibia, dorsally, H = male mesotibia, ventrally, I = labels of the holo-

Fig. 23. Asialassus kimurai, details of structure, male: A = head, ventral view, B = prothorax, ventral view, C = prosternal process, D = protibia, ventrally

Fig. 24. Asialassus tsushimanus, male, holotype: A = habitus, B = protibia, laterally, C = protibia, ventrally, D = mesotibia, E = aedeagus, dorsal view, F = prothorax, ventral view, G =

Fig. 25. Asialassus todai, male, holotype: A = habitus, B = prothorax, ventral view, C = prothorax, lateral view, D = protibia, dorsal view, E = protibia, ventral view, F = mesotibia, G =

Fig. 26. Asialassus adachii, male, holotype: A = habitus, B = protibia dorsally, C = protibia ventrally, D = mesotibia, E = prothorax, ventral view, F = prosternal process, lateral view, G = aedeagus, H = labels of the holotype