Iratiquedius, Brunke, 2022

Brunke, Adam J., 2022, A world generic revision of Quediini (Coleoptera, Staphylinidae, Staphylininae), part 1. Early diverging Nearctic lineages, ZooKeys 1134, pp. 129-170 : 129

Iratiquedius gen. nov.

Figs 2A-F , 3A, C-F , 4A-D , 6A-P , 7A-N , 9A-E

Type species.

Quedius amabilis Smetana, 1971.

Etymology.

The generic name is a combination of the Latin adjective ‘iratus’ and Quedius . It refers to the characteristic shape of the eyes, which are strongly convergent anteriad and create a comical, angry appearance.

Diagnosis.

Within Quediini , Iratiquedius can be distinguished from all other genera of the tribe by the distinctive eyes, which occupy nearly the entire lateral head margin, and are so convergent anteriad that their inner margin forms an obtuse angle with the suprantennal ridge (Fig. 3A ). The global diagnosis is the same as the regional Nearctic diagnosis.

Description.

Medium to small rove beetles, with variable coloration (Fig. 2A-F ). With the character states of Quediini (see Brunke et al. (2021)) and the following: antennomere 3 longer than 2, without dense setation; outer antennomeres (8-10) about as long as wide or shorter; antennae inserted close to inner margin of eye, separated by about the width of the antennal sclerite or less; head with eyes large, strongly convex, bulging from and nearly occupying entire lateral head outline, convergent anteriad and with inner margin forming obtuse angle with suprantennal ridge (Fig. 3A ); with basal puncture doubled (at least one side), interocular punctures present in some individuals of some species ( I. amabilis , I. mutator ) or absent, paraocular punctures absent, genal puncture absent (Fig. 3C, D ); frons not well-developed anterolaterad of antennal insertions; labrum notched medially, creating two lobes; apical maxillary and labial palpi fusiform and glabrous; infraorbital ridge complete to mandibles; gular sutures converging towards neck and narrowly spaced posteriad; mandibles with dorsal lateral groove absent or rudimentary, right mandible with single proximal tooth, tooth simple (Fig. 3D ) or bifid (Fig. 3C ); pronotum transverse to elongate, non-explanate, with three punctures in dorsal row, sublateral row at most reaching large lateral puncture, not extended posteriad; with only single large lateral puncture (e.g., Fig. 4A-D ); hypomeron strongly inflexed, not visible in lateral view; basisternum with pair of macrosetae (reduced in I. seriatus and I. prostans ) and well-developed longitudinal carina; scutellum impunctate; elytron with subbasal ridge complete and forming scutellar collar, disc without microsculpture between punctures; row of humeral spines present and well-developed; elytral punctation evenly distributed or in serial rows ( I. seriatus ); foretibia with lateral spines (reduced in I. seriatus , absent in I. prostans ) and apical spurs; metatarsomeres with disc setose; metatibia with at least three spines on outer face; abdominal tergite I with prototergal glands developed as moderately deep impressions, outer margin with row of setae; abdominal tergites not deeply impressed at base but some species with paired median impressions causing a ‘pinched’ appearance; abdominal sternite III with basal transverse line forming obtuse angle at middle, not produced posteriad; aedeagus with well developed paramere bearing peg setae; at least some species with discrete, paired internal sac sclerites that may be homologous with the ventral paired sclerites described by Brunke et al. (2016) (e.g., I. seriatus , I. uncifer (Fig. 7H-K )).

Distribution.

Iratiquedius is endemic to western North America.

Bionomics.

Species of Iratiquedius are most often found in wet moss, though I. prostans is more of a generalist and can be collected from a variety of wet debris along running water.

Comments.

The three included species of Iratiquedius ( I. amabilis , I. prostans , I. seriatus ) were resolved together in 'Clade A’ using a phylogenomic dataset ( Brunke et al. 2021). Although Clade A was recovered by the concatenated but not coalescent analyses, the morphological configuration of the eyes, unique in Quediini , provides strong further evidence for its monophyly.

Figures

Figure 2. A-H dorsal habitus of A, B Iratiquedius amabilis (Smetana) A male holotype B female non-type C, D I. mutator (Smetana) C male non-type D female holotype E I. prostans (Horn) F I. seriatus (Horn) G Paraquedius puncticeps (Horn) H P. marginicollis sp. nov. Scale bars: 1 mm.

Figure 3. A-D dorsal head A, B showing confluence of inner eye margin and supra-antennal carina (arrow) E, F abdominal tergites A, D Iratiquedius seriatus (Horn) B Quedius (Raphirus) probus (Casey) C, E I. amabilis (Smetana) F I. prostans (Horn). Abbreviations: af = anterior frontal puncture; b = basal puncture; pf = posterior frontal puncture; sa = supra-antennal puncture. Scale bars: 0.1 mm (A, B); 0.5 mm (C-F).

Figure 4. A-D anterior angle of the pronotum A, B Iratiquedius amabilis (Smetana) C, D I. mutator (Smetana) A, C macropterous morphotype B, D brachypterous morphotype. Scale bars: 0.1 mm.

Figure 6. A-G, L-O median lobe of aedeagus A-D, N, O in lateral view E-G, L, M in ventral view O with internal sac everted H-K, P underside of paramere showing peg setae A, B, E, F, H, I Iratiquedius amabilis (Smetana) C, D, G, J, K I. mutator (Smetana) L-P I. prostans (Horn). Scale bars: 0.1 mm.

Figure 7. A-K median lobe of aedeagus A-C in ventral view D-K in lateral view H, J internal sac partly everted, showing paired ventral sclerites I, K completely everted L-N underside of paramere showing peg setae A, B, D, E, H, I, L, M Iratiquedius seriatus (Horn) C, F, G, J, K, N I. uncifer sp. nov. Scale bars: 0.1 mm.

Figure 9. A-I female tergite X A Iratiquedius amabilis (Smetana) B I. mutator (Smetana) C I. prostans (Horn) D I. seriatus (Horn), evenly convex E I. uncifer sp. nov., discal impression F Paraquedius puncticeps (Horn) G P. marginicollis sp. nov. H-I Quediellus debilis (Horn). Pigmented area on tergite in E not shown for clarity but similar to I. seriatus. Scale bars: 0.1 mm.