Quedius (Microsaurus) impressithorax Scheerpeltz, 1965

Brunke, Adam James, 2023, Review of Quedius (Coleoptera, Staphylinidae) described from the 1934 expedition by R. Malaise to Myanmar, European Journal of Taxonomy 864, pp. 117-145 : 134-135

Quedius (Microsaurus) impressithorax Scheerpeltz, 1965

Figs 2E–F , 7F

Quedius (Microsaurus) impressithorax Scheerpeltz, 1965: 281 .

Diagnosis

Within the Kiangsiensis group, Quedius impressithorax may be distinguished by a combination of: small eyes, temples about 1.5 × as long as eyes ( Fig. 2F ); head slightly elongate, with posterior frontal puncture about three puncture diameters from eye margin ( Fig. 2F ); body entirely dark ( Fig. 2E ).

Type material

Holotype

MYANMAR – Kachin State • ♀; “ N.E. Burma , Kambaiti; 7000 ft.; 1/5.1934; R. Malaise [printed label] / HOLOTYPUS [red handwritten label] / TYPUS Quedius impressithorax, O. Scheerpeltz [dark red-pink label] / Quedius (Microsaurus) impressithorax nov. spec., det. Scheerpeltz [printed label] / 6590 E91 [blue printed label] / impressithorax Scheerpeltz [large, printed, folded label] / JLKB 000021054 ”; NHRS.

Redescription

Head, elytra, abdomen, antennae and legs dark brown, pronotum and apices of abdominal tergites slightly paler, dark reddish brown; apical tarsomeres of all legs paler, yellow-brown; abdomen vaguely iridescent. Head slightly longer than wide, with posterior angles indistinct; eyes small and only slightly protruding from lateral head outline, tempora longer than eyes, about 1.5 ×; without interocular punctures or additional punctures near the eye margin; posterior frontal puncture somewhat close to posterior margin of eye, about three puncture diameters, situated closer to margin of eye than to hind margin of head; temporal puncture slightly closer to posterior margin of head than margin of eye; surface of head with fine and dense microsculpture of transverse waves, becoming meshed at middle of disc, with distinct micropunctures moderately densely distributed. Antennae somewhat bulky, antennomere 4 only slightly transverse, 5–10 distinctly transverse, symmetrical, last segment shorter than previous two. Pronotum distinctly transverse, much wide than long, distinctly explanate laterally; dorsal rows with three punctures, sublateral rows with two punctures, not extended posteriad of large lateral puncture; microsculpture similar to that on head. Scutellum entirely and moderately densely punctate. Elytra at base distinctly narrower than pronotum, at both middle and sides, clearly longer than pronotum; punctures rather fine and dense, many punctures touching laterally; pubescence pale, yellow-brown; disc without microsculpture. Wing fully developed. Abdomen with tergite VII with palisade fringe; punctation sparser than that of elytra, punctures clearly separated by their diameter or more; tergite III with very small sparsely punctate area at middle; tergites with extremely fine microsculpture of transverse waves.

Male

Unknown.

Female

Tergite X elongate triangular, strongly narrowed to acutely projected apex, sides of apex sinuate, disc with median darkening from about posterior two-thirds to apex ( Fig. 7F ).

Distribution

Known only from the type locality in Myanmar (Kachin).

Remarks

The posterior frontal puncture is located at a distance from the eye that is similar to Q. kubani Smetana, 1996 and Q. kuatunensis Smetana, 2013 but in these species the head is clearly transverse, the eyes are larger and the apical antennomeres are asymmetrical. Quedius impressithorax keys to Q. albiorix Smetana, 2012 (Sichuan, China) in Smetana (2017a) but is quite different in habitus, with entirely dark antennae, a longer head and a distinctly less distant posterior frontal puncture (4–5 puncture diameters in Q. albiorix ). Quedius impressithorax is here provisionally treated as a valid species until males are found at or near the type locality.

Figures

Fig. 2. A–E. Dorsal habitus. A. Malaisdius ruficeps (Scheerpeltz, 1965), ♂, paratype (NHW). B. Malaisdius smetanai gen. et. sp. nov., ♂, holotype (NME). C. Quedius (Microsaurus) rutilipennis Scheerpeltz, 1965, ♂, holotype (NHRS). D. Q. (M.) piceolineatus Scheerpeltz, 1965, ♂ holotype (NHRS). E. Q. (M.) impressithorax Scheerpeltz, 1965, ♀ holotype (NHRS). F. Forebody of Q. (M.) impressithorax Scheerpeltz, 1965. Abbreviation: Pf = posterior frontal puncture. Scale bars = 1 mm.

Fig. 7. Female tergite X. A. Indoquedius dispersepunctatus (Scheerpeltz, 1965). B. I. parallelicollis (Scheerpeltz, 1965). C. I. recticollis (Scheerpeltz, 1965). D. Malaisdius ruficeps (Scheerpeltz, 1965). E. Quedius (Microsaurus) rutilipennis Scheerpeltz, 1965. F. Q. (M.) impressithorax Scheerpeltz, 1965. Scale bars = 0.1 mm.