Cyanocypus, He & Zhou, 2020

He, Liang & Zhou, Hong-Zhang, 2020, Cyanocypus gen. nov., a new rove beetle genus of the “ Staphylinus-complex ” (Coleoptera: Staphylinidae) with one new species from China, Zootaxa 4759 (2), pp. 261-268 : 262-264

Cyanocypus gen. nov.

( Figs. 1 , 3 , 4 )

Type species. Cyanocypus leukos sp. nov. (by monotypy).

Diagnosis. The new genus Cyanocypus gen. nov. differs from other members of the “ Staphylinus -complex” by the following characteristics: mandibles each with one simple tooth in middle of medial margin and with a deep subbasal emargination ( Figs. 1 C, D ); last segment of maxillary palpus narrowly fusiform, with narrowly rounded apex, asetose; last segment of labial palpus setose, widely fusiform, with widely obliquely truncate apex ( Fig. 3 A ); abdominal tergites with oblique accessory basal ridges; sensory peg setae numerous, distributed from apex to basal part of underside of paramere ( Fig. 3 E ).

Description. Head, pronotum and elytra with shining blue metallic luster. Mandibles moderately long, each on medial margin with subbasal emargination, and with one simple tooth in middle ( Figs. 1 C, D ). Mandibular prostheca with supporting structure long and lanceolate, with ciliae along medial margin short near basal part, but gradually becoming longer towards apex. Gular sutures subcontiguous in middle section. Maxillary palpus moderately long, last segment narrowly fusiform, with narrowly rounded apex, asetose. Labial palpus with last segment setose, widely fusiform, with widely obliquely truncate apex. Pronotal epimeron absent. Pronotal hypomeron glabrous. Superior and inferior lines of pronotal hypomeron join together at about anterior third of pronotal length; deflected portion of pronotal disc largely visible in ventral view at anterior angles of pronotum. Prosternum with sternacostal ridge bisinuate. Mesosternum short; intercoxal process narrow, quite acute apically. Elytra moderately long, not markedly depressed along base; wings fully developed. Metasternum long; anterior projection of metasternum broadly rounded, with acutely converging margins. Dorsolateral face of front tibia with a few spines on apical part; long spines on dorsolateral face of middle tibia robust, quite numerous; dorsolateral face of hind tibia with long spines only on apical half, distinctly shorter and fewer than those on middle tibia. Empodial setae moderately long, distinctly not reaching apex of claws. First three visible abdominal tergites with oblique basal lines extending posteriad from anterior basal line, base of tergite between extensions markedly transversely impressed; lateral parts of first three visible tergites and almost all the surface of visible tergite 5 covered with long silver pubescence.

Male genital segment with tergite 8 moderately wide, with obtusely triangular medioapical emargination; sternite 9 with tapered basal portion moderately long, apical portion with wide and deeply rounded medioapical emargination; tergite 10 subtriangular, obtusely angular at apex; aedeagus with sensory peg setae on underside of paramere extremely numerous, arranged from apical to basal part of apical portion of paramere.

Recognition and comments. The new genus Cyanocypus gen. nov., at present, contains only the type species Cyanocypus leukos sp. nov. It can be easily distinguished from other members of the “ Staphylinus -complex” by the characteristics listed above under Diagnosis, especially the mandibular characters. Mandible morphology is now considered as an important character system for distinguishing the genera of the “ Staphylinus -complex” ( Smetana, 2003). Smetana (2003) provided a summary of the types of mandible shape in the “ Staphylinus -complex”; however, the mandible morphology of Cyanocypus gen. nov. does not belong to any of those types. In this new genus, each mandible has a wide subbasal indentation and one simple tooth in the middle, easily distinguishing it from Ocypus and similar genera. A similar kind of wide subbasal indentation occurs in the species of Protocypus , but the tooth in the middle of the mandibles of Protocypus is bidentate ( Fig. 2C ). The new genus shares the modification of the abdominal tergites (first three visible abdominal tergites with accessory basal lines, base of tergite between these lines transversely impressed) with the genus Aulacocypus J. Müller , the “ bisinuatus -group” of the genus Sphaerobulbus Smetana , and the genera Nelmanwaslus Smetana and Wasmannellus Bernhauer. From these genera, Cyanocypus gen. nov. can be easily distinguished by the subbasal mandibular indentation ( Figs. 2 A, B ).

The numerous sensory peg setae as well as their arrangement on underside of the paramere of Cyanocypus gen. nov. are also quite unique in the Staphylinus complex. In all other genera or species of the Staphylinus complex with sensory peg setae, they are mostly situated on apical to middle portion on the underside of paramere, never stretching far towards the base of paramere. In Cyanocypus gen. nov. the sensory peg setae are widely extended from apical to basal portion of the paramere ( Fig. 3 E ). This character state seems to be an autapomorphy of the new genus Cyanocypus gen. nov., but this requires further study.

Brunke & Smetana (2019) characterized the major lineages of subtribe Staphylinina and according the abovementioned characters of Cyanocypus gen. nov., it is possible to include this new genus in the Ocypus group.

Etymology. The new genus name Cyanocypus (masc.) is derived from the combination of the Greek term Cyan- (dark blue) and Ocypus (the known genus name used for a long time).

Figures

FIGURE 1. Cyanocypus leukos He & Zhou, sp. nov.: A. habitus, dorsal view (2.0 mm); B. habitus, ventral view (2.0 mm); C. left mandible (0.5 mm); D. right mandible (0.5 mm). Scales in parentheses.

FIGURE 2. Dorsal view of head:A. Cyanocypus leukos He & Zhou, sp. nov.; B. Sphaerobulbus yunnanus Smetana; C. Protocypus taibaiensis He & Zhou. Scale bars = 0.50 mm.

FIGURE 3. Cyanocypus leukos He & Zhou, sp. nov.: A. head, ventral view; B. head, dorsal view; C. aedeagus, lateral view; D. aedeagus, ventral view; E. underside of apical portion of paramere. Scale bars = 0.50 mm.

FIGURE 4. Cyanocypus leukos He & Zhou, sp. nov.: A. underside of apical portion of paramere; B and D. aedeagus, lateral view; C. aedeagus, ventral view; E. male tergite 10; F. apical portion of median lobe, ventral view, paramere removed; G. male sternite 9; H. male sternite 8. Scale bars = 0.50 mm.