Key to species and species groups of Quedius sensu stricto

1 Presence of 4 or 6 additional setiferous punctures between anterior frontal punctures (Fig. K1A). Palearctic, two species introduced to the Nearctic. Q. fuliginosus -group .................................................. 5

– Presence of 2 or no additional setiferous punctures between anterior frontal punctures (Fig. K1B). ..... 2

2 Presence of 2 additional setiferous punctures between anterior frontal punctures (Fig. K2A). Nearctic. Q. molochinoides -group ..................................... 15

– No additional setiferous punctures between anterior frontal punctures (Fig. K2B). ................................. 3

3 Additional 1 to 3 punctures in the posterior half of the sublateral row (Fig. K3A). W Palearctic. Q. pallipes - group ...................................................................... 8

– No additional puncture in the posterior half of the sublateral row (Fig. K3B). ..................................... 4

4 Palearctic. Q. molochinus -group .......................... 9

– Nearctic. Q. laticollis -group and Q. molochinus introduced from Palearctic. .................................. 19

5 Scutellum punctured and pubescent (Fig. K5A). W Palearctic, usually preferring warmer drier habitats. ................................. Quedius levicollis Brullé, 1832

– Scutellum unpunctured and glabrous (Fig. K5B). ......................................................................................6

6 Head with 4 additional punctures between posterior frontal punctures, but without additional puncture between anterior and posterior frontal punctures (Fig. K6A). Median lobe without apical ridge. Paleartic. Introduced to multiple Nearctic localities. ............. 7

– Presence of 4 additional punctures between posterior frontal punctures and one additional puncture on either side between anterior and posterior frontal punctures (Fig. K6B). Median lobe with apical ridge (Fig. 14A). Palearctic, known only from North Africa and the islands of Sardinia and Corse. ...................... .................. Quedius afrofuliginosus Gusarov, 1991

7 Basal three antennomeres at least slightly darkened. Eyes clearly protruding making the head seem more rectangular wider across (Fig. K7A). Apex of median lobe not laterally flattened (Fig. 14D). Palearctic. Introduced to E Canada. Prefers wetter humus rich habitats. Paleartic. Introduced to multiple Nearctic localities. ................................................................... ................. Quedius fuliginosus (Gravenhorst, 1802)

– Basal three antennomeres completely pale. Eyes not clearly protruding making the head seem round (Fig. K7B). Apex of median lobe laterally flattened (Fig. 14C). Paleartic. Introduced to multiple Nearctic localities. ..... Quedius curtipennis Bernhauer, 1908

8 Sides of median lobe apex folded with distinct tooth situated at lower part (Fig. 15C). Western Europe along Atlantic Coast from Denmark to Iberia and inland in Southern France and Iberian Peninsula, also on the islands of Madeira, Azores, Canaries, and Balearic (Fig. K8A). .................................................. ....................... Quedius hispanicus Bernhauer, 1898

– Sides of median lobe apex folded with distinct tooth situated at medial part (Fig. 15D). North Africa, Italy and islands of Sardinia and Corse (Fig. K8B). .......... ................................... Quedius pallipes Lucas, 1846

9 Elytra shortened, distinctly shorter than pronotum (Fig. K9A), obviously brachypterous species without whitish apical seam on abdominal tergite VII (Fig. 11F). East Palearctic. ................................................. .......................... Quedius sundukovi Smetana, 2003

– Elytra normal, not shortened, about as long as pronotum (Fig. K9B), with whitish apical seam on abdominal tergite VII. ............................................................ 10

10 Basal three antennomeres at least slightly darkened (Fig. K10A). ......................................................... 11

– Basal three antennomeres pale (Fig. K10B). ....... 13

11 Elytra most often reddish, very rarely darkened. Appendages only slightly darkened. Tibia, tarsi and apical antennomeres of antennae pale reddish brown (Figs K11A, 11E). Found near water bodies in Central-Eastern Europe and Middle Asia (Fig. 23). .. .................................. Quedius balticus Korge, 1960

– Elytra always dark. Appendages darkened. Tarsi slightly paler brown to dark brown at most (Figs K11B, 10E–F). Found at higher elevations or latitudes (Figs 25, 27). .......................................... 12

12 Head disc with fine isodiametric microsculpture (Fig. K12A). Without C-sclerite of the internal sac (Fig. 16A). Found at alpine sites of Central and Southern Europe (Fig. K12C). .................................................. ...................... Quedius unicolor Kiesenwetter, 1847

– Head disc most often with microsculpture of fine transverse waves, rarely isodiametric (Fig. K12B). With clear C-sclerite of the internal sac (Fig. 15C). Found disjunct in boreal Scandinavia and Russia, as well as alpine in Altai Mountains and Transbaikalia (Fig. K12D). ..... Quedius subunicolor Korge, 1961

13 Body brown. Elytra yellowish red. Apex of paramere pointing ventral, away from median lobe in form of a small blunt hook (Figs K13B, 15A). Central Anatolia, Middle East, Transcauscasus, Central Asia (Fig. K13A). ..... Quedius vicinus (Ménétriés, 1832)

– Body most often black, or at most brownish. Elytra brick or brownish red. Apex of paramere straight, not pointing ventrad, away from median lobe (Figs K13C–D, 15D, 15F). Distribution more northern (Figs K14A–B)...................................................... 14

14 C-shaped sclerite of internal sac without spine-like basal extension (Figs K13C, 15F). SE European distribution (Fig. K14A). ........................................... ........... Quedius meridiocarpathicus Smetana, 1958

– C-shaped sclerite of internal sac with spine-like basal extension (Figs K13D, 15D). N Palearctic distribution (Fig. K14B). ........................................... ............... Quedius molochinus (Gravenhorst, 1806)

15 Basal three antennomeres pale and antennae more elongate (antennomere 10 clearly longer than wide) (Fig. K15A). Elytra light to dark brown. Generally larger. Forebody length 5.49–5.93 (5.78) mm (Fig. 13F). Boreal North America (Fig. 28). ...................... ..................... Quedius labradorensis Smetana, 1965

– Basal three antennomeres darkened and antennae more robust (antennomere 10 more or less transverse) (Fig. K15B). Elytra black or reddish. Generally smaller. Forebody length 4.97–5.86 (5.39) mm. ........................................................... 16

16 Paramere with basal attenuation and broadening towards apex forming a spoon like shape, peg setae situated in a semi-circle along the edge of the paramere (Figs K16A, 8, 17B). Coastal to mid elevation from Oregon to Southern Alaska including Vancouver and Haida Gwaii. ..................................... ...................................... Quedius horni Hatch, 1957

– Paramere only with at most slight attenuation forming a lanceolate shape (Figs K16B–D). ...................... 17

17 Distributed across Boreal North America. South of the Northern Rocky Mountains (Fig. K17A). Teeth of median lobe clearly folded inwards (Figs K16B, 17E). ......... Quedius molochinoides Smetana, 1965

– Central and Southern Rocky Mountains, Cascades, Blue Mountains and Sierra Nevada (Fig. K17B). Teeth of median lobe either protruding or not clearly formed (Figs K16C–D). ....................................... 19

18. Found in the Cascades, Blue Mountains and Sierra Nevada (Fig. K18A). Paramere and median lobe clearly broader (Figs K16C, 17D). ............................ ....................................... Quedius lanei Hatch, 1957

– Found in Central and Southern Rocky Mountains (Fig. K18B). Paramere and median lobe clearly more slender (Figs K16D, 17C). ........................................ ........................................... Quedius altanai sp. nov.

19 Paramere rather slender and clear C-sclerite of the internal sac (Figs K19A, 15D). Introduced in parts of Eastern North America, seems to be spreading. ........ ............... Quedius molochinus (Gravenhorst, 1806)

– Paramere rather broad and No C-sclerite of internal sac (Figs K19B–C). Q. laticollis -group .............. 20

20 Peg setae of paramere forming a solid triangular field, usually with two wide and short extensions posteriorly (Figs K20A, 16E). E North America (Fig. K20B). ........ Quedius laticollis (Gravenhorst, 1802)

– Peg setae of paramere arranged into two short longitudinal rows, which more or less diverge posteriorly (Figs K20C, 16F). Great American Plains (Fig. K20D). ........... Quedius strenuus Casey, 1915