Zhou, Yin & Zhou, 2024

Yin, Zi-Wei & Zhou, De-Yao, 2024, Chenzhilinus, a new subgenus of Euconnus Thomson (Coleoptera: Staphylinidae: Scydmaeninae) from southern China, Zootaxa 5541 (4), pp. 582-592 : 583-587

publication ID

https://doi.org/ 10.11646/zootaxa.5541.4.9

publication LSID

lsid:zoobank.org:pub:4BB31837-9CF2-4C04-906B-5B741D3AA47A

persistent identifier

https://treatment.plazi.org/id/039E87AC-FFB9-2D12-E0DF-794EFF4BFC63

treatment provided by

Plazi

scientific name

Zhou
status

subgen. nov.

Chenzhilinus Yin & Zhou , subgen. nov. (of Euconnus )

Chinese common name: ŘNJṀẆŵm亚¶

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

Type species: Euconnus (Chenzhilinus) huapingensis sp. nov.

Diagnosis. Chenzhilinus differs from all other subgenera by two potentially apomorphic character states, e.g., submentum laterally demarcated by additional pair of hypostomal carinae, and aedeagus lacking parameres, plus following combination of characters variably present in Euconnus s. str. species: antennae with tetramerous antennal club composed of four distinctly enlarged antennomeres; bristles present on vertex, tempora, and gene of head, anterolateral, lateral, and lateroventral area of pronotum, and mesanepisternum of the thorax; pronotum broadest at middle, weakly convergent from broadest point posteriorly, with pair of large antebasal pits, lacking sublateral carinae; hypomeral ridges and notosternal sutures complete; mesoventral intercoxal process broad, keel-like, entirely greatly projecting ventrally; elytra each with two large basal pits, humeral calli projected, metathoracic wings fully developed.

Description. Male. General body shape ( Fig. 1 View FIGURE 1 ) elongate, body deeply constricted between head and pronotum; head, prothorax, and elytra weakly convex; appendages moderately long and slender, vestiture of setae normally developed, thick bristles present on vertex, tempora, and gene of head, and anterolateral, lateral, and lateroventral area of pronotum, anterolateral margins of mesothorax and on metaventrite. Pigmentation of cuticle reddish-brown.

Head capsule ( Figs 2A, C View FIGURE 2 , 3A View FIGURE 3 ) divided by occipital constriction into large anterior and small posterior part (‘neck region’), posterior part retracted into pronotum. ‘Neck’ region much narrower than vertex, short and subcylindrical; narrowest site of occipital constriction about as wide as half head width. Anterior part of head ‘anthiciform’, i.e., approximately pentagonal, broad and flattened, broadest at anteriorly located eyes. Dorsum of head ( Fig. 2C View FIGURE 2 ) almost flat; tempora ( Fig. 2A, C View FIGURE 2 ; tm) much longer than compound eyes ( Fig. 2C View FIGURE 2 ; ce) and with bristles; vertex ( Fig. 2A, C View FIGURE 2 ; vt) strongly transverse, anteriorly confluent with subtrapezoidal, transverse frons, which is steeply lowering anteriorly in front of weakly raised supraantennal tubercles; frons and vertex sparsely setose; genae ( Figs 2C View FIGURE 2 , 3A View FIGURE 3 ; gen) and postgenae together elongate, convex, covered with thick bristles. Clypeus ( Fig. 2A–C View FIGURE 2 ; cl) confluent with frons ( Fig. 2A–C View FIGURE 2 ; fr), lacking frontoclypeal groove. Ventral side of head ( Figs 2C View FIGURE 2 , 3A View FIGURE 3 ) flattened; gular plate ( Figs 2E View FIGURE 2 , 3A, B View FIGURE 3 ; gp) lacking sutures, anterior part adjacent to posterior tentorial pits with convergent margins; posterior tentorial pits ( Fig. 3A View FIGURE 3 ; ptp) elongate, located anteriorly to transverse impression separating ‘neck’ region from anterior part of head.

Mouthparts ( Figs 2B View FIGURE 2 , 3A View FIGURE 3 ). Labrum ( Fig. 2B, C View FIGURE 2 ; lb) transverse, with rounded and anteriorly roundly convergent sides and broadly rounded anterior margin with broad and shallow median emargination, dorsal surface with one transverse row of long setae and epipharynx with several elongate sensilla extending anteriorly beyond anterior labral margin and visible in dorsal view. Mandibles ( Figs 2B, C View FIGURE 2 , 3A View FIGURE 3 ) symmetrical, moderately large, broad only at base and curved, markedly slender, with pointed apical tooth, and small tooth ( Figs 2B View FIGURE 2 , 3A View FIGURE 3 ; mt) located at submedian region of mesal mandibular margin; prostheca elongate, composed of numerous dense trichia occupying narrow sub-basal mesal area. Maxilla ( Fig. 3A View FIGURE 3 ) elongate, with transverse cardo; subtriangular and elongate basistipes; elongate and broad mediostipes; elongate galea and lacinia with long and dense trichia along distal and mesal margin; maxillary palpus ( Figs 2B, C View FIGURE 2 , 3A View FIGURE 3 ; mp, mp1–4) long and slender, palpomere 1 small but strongly elongate, 2 long and distinctly thickening distally, pipe-like, 3 longer than 2 and strongly broadening distally, broadest near middle, 4 small, subconical and slender, with elongate and pointed apical palpal cone. Labium with subtriangular submentum ( Fig. 3A View FIGURE 3 ; smn) laterally demarcated by pair of posteriorly convergent hypostomal carinae ( Fig. 3A View FIGURE 3 ; hc); mentum ( Fig. 3A View FIGURE 3 ; mn) subtrapezoidal; prementum short, with distinctly demarcated, glabrous ligula; labial palps ( Figs 2C View FIGURE 2 , 3A View FIGURE 3 ) much shorter than mentum, palpomere 1 short, 2 strongly elongate and weakly broadening distally, 3 long and slender, narrowing distally. Posteriorly and laterally mouthparts demarcated by hypostomal ridges ( Fig. 3A View FIGURE 3 ; hr) which are moderately curved and extending nearly up to posterior tentorial pits, but posteriorly not connected.

Antennae ( Figs 1 View FIGURE 1 , 2D View FIGURE 2 ) moderately slender and moderately long, antennomeres 1–7 compact, four terminal antennomeres forming distinct club ( Fig. 2D; a View FIGURE 2 8–11). All antennomeres covered with sparse long setae.

Prothorax ( Figs 1 View FIGURE 1 , 2E View FIGURE 2 , 3B View FIGURE 3 ) weakly convex, in dorsal view ( Fig. 1A View FIGURE 1 ) bell-shaped, broadest near middle; lateral margins slightly convergent posteriorly from broadest point. Pronotum ( Fig. 2A, E View FIGURE 2 ; pr) lacking sublateral carinae. Base of pronotum with only one pair of relatively large and deep lateral antebasal pits ( Figs 2A View FIGURE 2 , 3C View FIGURE 3 ; abp). Pronotal disc regularly setose, lateral portions above hypomeral ridges with thick and dense bristles ( Fig. 2E View FIGURE 2 ). Prosternum ( Fig. 3B View FIGURE 3 ) about half as long as pronotum, with basisternal part ( Fig. 3B View FIGURE 3 ; bst) short and indistinctly demarcated from procoxal cavities; prosternal intercoxal process indistinct, developed as diffused median longitudinal elevation; procoxal sockets closed by posterolateral expansions of prosternum and posteromesal lobes of hypomera. Hypomera elongate, with strongly curved inner (adcoxal) margins, each divided by entire hypomeral ridge ( Figs 2E View FIGURE 2 , 3B View FIGURE 3 ; hyr) into small subtriangular inner (adcoxal) part ( Fig. 3B View FIGURE 3 ; ihy) and large external part fused with sides of pronotum; notosternal sutures ( Fig. 3B View FIGURE 3 ; nss) complete and arcuate.

Elytra ( Fig. 1A, C View FIGURE 1 ) together suboval and relatively slender, dorsally flattened, with rounded apices; elytral base about as broad as pronotal base, with projecting humeral calli ( Fig. 3C View FIGURE 3 ); each elytron with two distinct asetose basal elytral pits ( Fig. 2A View FIGURE 2 , 3C View FIGURE 3 ; bep). Metathoracic wings fully developed.

Mesoventrite ( Fig. 3D View FIGURE 3 ) moderately short, much broader than long, with broad anterior ridge bearing subtriangular median projection connected with long, slender and keel-like mesoventral intercoxal process ( Fig. 3D View FIGURE 3 ; msvp) greatly raised ventrally ( Fig. 1C View FIGURE 1 ; msvp), process posteriorly fused with metaventrite, with broad intercoxal portion; mesoventrite posterior to anterior ridge with pair of broad, sparsely setose impressions functioning as procoxal rests ( Fig. 3D View FIGURE 3 ; pcr) separated from mesocoxal cavities by slightly oblique ridge; mesocoxal sockets located laterally. Prepectus (Fig. 14; pre) massive, posterior part of mesanepisternum partly visible in ventral view, with dense lateral bristles ( Fig. 3D View FIGURE 3 ).

Metaventrite ( Fig. 3D View FIGURE 3 ) much longer than mesoventrite, subquadrate in shape, anteriorly fused with mesoventrite, lateral margins slightly rounded, lateral (admetacoxal) parts of posterior margin slightly curved, at middle posterior margin expanded posteriorly and forming relatively narrow and subtrapezoidal metaventral intercoxal process ( Fig. 3D View FIGURE 3 ; mtvp); most part of ventrite distinctly punctate and covered with long setae, in anterior part with sparse and thick bristles at middle.

Legs moderately long and slender; mesotibia in male with preapical setose tuft ( Fig. 2F View FIGURE 2 ); tarsomeres lacking ventrodistal lobes.

Abdomen ( Fig. 1B View FIGURE 1 ) elongate, roundly triangular; abdominal sternites III–VIII gradually narrowing towards abdominal apex, sternite III longest, with shallow metacoxal cavities each demarcated posteriorly by curved coxal line; suture between sternite VII and VIII less distinct than between remaining sternites. Propygidium hidden under elytra, weakly sclerotized; pygidium exposed in intact specimens, strongly sclerotized, subtriangular with rounded apex, covered with setae. Sternite IX large, broad and transverse, with nearly straight anterior margin, lateral margins weakly and evenly divergent posteriorly; tergite IX reduced to lateral apodemes fused with posterolateral margins of sternite IX; tergite X subtrapezoidal, with almost straight posterior margin.

Aedeagus ( Fig. 4 View FIGURE 4 ) with symmetric median lobe, moderately stout; dorsal and ventral plate discriminated vaguely by archived suture; endophallus symmetric, with two sclerotized components at middle; parameres absent.

Female. Unknown.

Etymology. The new generic name is dedicated to Zhi-Lin Chen, who provided continuous support during our field activities in Guangxi.

Included species. This subgenus currently includes only one species (described below) distributed in Guangxi, southern China.

Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF