Sundaquedius Brunke, 2021

Brunke, Adam J., 2021, New relictual genera in Cyrtoquediini and Indoquediini (Coleoptera: Staphylinidae: Staphylininae), ZooKeys 1076, pp. 109-124 : 109

Sundaquedius Brunke gen. nov.

Figs 1A-F , 2A-G

Type species.

Sundaquedius abbreviatus Brunke, sp. nov.

Etymology.

The generic name refers to the Sunda Plate and Quedius , with which members of this genus and closely related genus Cyrtoquedius were associated with for a long time. Much of the Sunda Plate is currently below sea level but had connected terrestrial species on Borneo, Sumatra, Java and the present southeast Asian mainland in multiple episodes, from about the Eocene to as recently as the Pleistocene (e.g., Inger and Voris 2001). Noun in apposition.

Diagnosis.

Among other Oriental Cyrtoquediini , Sundaquedius is easily recognized by a combination of the large eyes (more than 3 × as long as temples) (Fig. 1B, E ), incomplete infraorbital ridge and elytra with rows of setose punctures. It can be distinguished from its putative close relatives Cyrtoquedius and Parisanopus by any one of: more than one puncture in the dorsal row of the pronotum (Fig. 1C, F ), two or more parocular punctures on the head (Fig. 1B, E ), the incomplete infraorbital ridge and presence of peg setae on the paramere (Fig. 2B ).

Description.

With the character states of Cyrtoquediini (see Brunke et al. 2021) and the following: head with basal puncture present but not doubled; two or three parocular punctures present; antennae non-geniculate, antennomeres 1-3 sparsely pubescent and without tomentose pubescence, antennomere 4 with some tomentose pubescence but much sparser than 5; labrum with two usual lobes and moderately incised median emargination; apical maxillary and labial palpi fusiform, apical labial palpomere with sparse, short setae; mandibles slender in apical half and markedly broad in basal half, bearing a single proximal tooth; gular sutures convergent, separate but running extremely close in basal half; infraorbital ridge/nuchal ridge incomplete, reaching ~ 1/3 to 1/2 the distance to mandible base; pronotum strongly convex, non-explanate and slightly elongate, with 2-8 punctures in the dorsal row, ‘second’ puncture present; basisternum with pair of macrosetae at middle; mesoscutellum glabrous and without micropunctures; disc of elytra without microsculpture and glabrous, except for three rows of coarse setose macropunctures (one sutural, two discal), rows slightly disorganized due to extra punctures in S. nigropolitus ; elytra with epipleuron bearing row of coarse, setose macropunctures, epipleuron with additional rows and clusters of coarse setae; epipleural margin not thickened; mesocoxae contiguous; metatibia spinose, with three spines on outer face, inner face without spines; pro- and metatarsomeres with setae on disc, setae not restricted to margins; metatarsomere 4 with ventral setae distinctly interrupted medially and removed from apical margin; abdominal tergite IV with impression but punctures only slightly more impressed, not markedly coarser in impression (as in Bolitogyrus ); abdominal sternite III with basal transverse line sharply produced posteriad forming an acute angle at middle; abdominal sternite IV with basal transverse line not produced; aedeagus with single fused paramere bearing well-developed peg setae, internal sac with ventral, paired copulatory sclerites, with an additional sclerotized structure similar to dorsal copulatory piece, but singular, and more weakly sclerotized compared to Cyrtoquedius or Parisanopus , and held within spinose internal sac.

Distribution.

Sundaquedius is presently known only from central Vietnam and East Java but likely occurs at medium elevations across southeast Asia, west of Wallace’s line.

Bionomics.

Nothing is known about the bionomics of this genus, except that both species were collected in lower montane forests (700-1500 m). Sundaquedius might be collected by sifting moist litter, like many species of the related genus Cyrtoquedius .

Comments.

In recent phylogenomic analyses, Sundaquedius was recovered as the sister group of Nearctic/Neotropical genus Cyrtoquedius with high support, though few genera of Cyrtoquediini were included in the taxon sample ( Brunke et al. 2021). Sundaquedius is probably most closely related to Cyrtoquedius , or perhaps Cyrtoquedius + Parisanopus , based on morphological similarity (see above key).

Figures

Figure 1. Sundaquedius Brunke A-C S. nigropolitus (Cameron) D-F S. abbreviatus Brunke A, D habitus B, E dorsal head, arrows indicating anterior and posterior frontal punctures, asterisks indicating parocular punctures C, F dorsal pronotum, arrows indicating punctures of the dorsal row. Scale bars: 1 mm.

Figure 2. Sundaquedius Brunke A-F S. abbreviatus Brunke G S. nigropolitus (Cameron) A aedeagus, ventral view B apex of paramere, underside C aedeagus, lateral view (paramere removed) D male tergite X E male sternite IX F, G female tergite X. Scale bars: 0.25 mm (A-C); 0.5 mm (D-G).