Malaisdius ruficeps ( Scheerpeltz, 1965 ) Brunke, Adam James, 2023

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 : 128-129

Malaisdius ruficeps ( Scheerpeltz, 1965) comb. nov.

Figs 2A , 5A , 6A–E , 7D

Quedius (Microsaurus) ruficeps Scheerpeltz, 1965: 286 .

Diagnosis

Within the genus, M. ruficeps comb. nov. is easily distinguished from M. smetanai gen. et sp. nov. by the strikingly bicolored body ( Fig. 2A ).

Type material

Holotype

MYANMAR – Kachin State • ♂; “ N.E. Burma , Kambaiti; 7000 ft.; 12/5 193; R. Malaise [printed label] / Holotypus [handwritten red label] / TYPUS Quedius ruficeps, O. Scheerpeltz [typed dark red-pink label] / Quedius (Microsaurus) ruficeps nov. spec., det. Scheerpeltz, 1974 [white label] / 6693 E91 [typed blue label] / NHRS-JLKB 000021051 [identifier]”; NHRS.

Paratypes

MYANMAR – Kachin State • 1 ♀; “[card with female symbol] / N.E. Burma , Kambaiti; 2000 m; 24/5.1934; Malaise [typed label] /Schwedisch Indian-Burma Expedition 1934 [typed label] /ex. coll. Scheerpeltz [typed blue label] / Allotypus [handwritten red label] / TYPUS Quedius ruficeps, O. Scheerpeltz [typed dark red-pink label] / ruficeps Schp [handwritten pink card]; NHW • 1 ♀; “[card with female symbol] / N.E. Burma , Kambaiti; 7000 ft.; 28/5 1934; R. Malaise [printed label] / Schwedisch Indian-Burma Expedition 1934 [typed label] /ex. coll. Scheerpeltz [typed blue label] / COTYPUS Quedius ruficeps O. Scheerpeltz [pink label]”; NHW • 1 ♂; “ N.E. Burma , Kambaiti; 2000 m; 25/5.1934; Malaise [typed label] / COTYPUS Quedius ruficeps O. Scheerpeltz [pink label] / 6694 E91 [typed blue label] / NHRS-JLKB 000021052 [identifier] / ruficeps Scheer [large folded label]”; NHRS .

Redescription

Head and pronotum pale orange-red, sharply contrasting with dark, vaguely bluish elytra and abdomen, scutellum very dark red, abdomen with iridescent reflection, antennomeres 1–4 pale, yellow, antennomeres 5–11 darker, brown to dark brown, becoming darker toward apex of antenna, legs entirely pale, yellow, palpi entirely pale, yellow. Body length (minus abdomen): 3.8–4.3 mm. Head slightly wider than long (1.12–1.15), with posterior angles absent; neck varying from moderately wide to narrow, creating an impression of a more elongate head; eyes large and clearly protruding from lateral head outline, tempora shorter than eyes (0.4–0.6); temporal puncture much closer to eye margin than hind margin of head; surface of head with extremely fine and superficial microsculpture of dense transverse waves. Antennae long, all segments longer than wide except 8–10, which are weakly transverse and slightly asymmetrical. Pronotum strongly convex, about as wide as long to distinctly wider than long (1.20), slightly explanate, punctures arranged as in generic description, microsculpture similar to that on head. Scutellum impunctate. Elytra at base slightly broader than pronotum, at middle and sides distinctly longer than pronotum at midline; disc without microsculpture, punctures sparsely and irregularly spaced, deeply impressed and foveate. Wings fully developed. Abdomen with tergite VII with palisade fringe; punctation as in generic description; tergites with extremely fine microsculpture of transverse waves.

Male

Sternite VIII with distinct but shallow emargination that is about 3.0 × as wide as long; sternite IX with long, asymmetrical basal part, most of disc setose, narrowing to asymmetrically rounded and entire apex; tergite X weakly narrowed to truncate and loosely crenulate apex, projections bearing setae; median lobe and paramere asymmetrical; median lobe in ventral view with apical third delimited by slight constriction, narrowed to rounded acute apex, with one lateral and one median fin-like tooth ( Fig. 6A–B ); median lobe in lateral view with narrowed apical part distad of emargination, this part with a tooth corresponding to the lateral tooth in ventral view, median tooth clearly visible ( Fig. 6C ); in the alternate lateral view, median lobe with apical part appearing broader and median tooth less visible ( Fig. 6D ); paramere broad and subparallel over much of its length, narrowing into a finger-like lobe, with a small lateral bulge, apex with four pairs of small setae, peg setae absent ( Fig. 6E ).

Female

Tergite X ( Fig. 7D ) nearly oval in shape, narrowed to moderately wide and slightly acuminate apex, disc with distinct oval impression, apex with pair of very long setae.

Distribution

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

Remarks

One of the female paratypes is slightly paler than the other individuals, the antennae appear narrower, with antennomeres 7–10 weakly transverse, and the elytra appear vaguely narrower. However, this is considered to be intraspecific variation.

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. 5. A. Malaisdius ruficeps (Scheerpeltz, 1965), dorsal abdomen. B. M. smetanai gen. et sp. nov., dorsal abdomen. C–E. Quedius (Microsaurus) rutilipennis Scheerpeltz, 1965. C. Antenna. D. Pronotum (white arrow: marginal punctures removed from marginal bead; black arrow: anterior angles with marginal bead entirely visible in dorsal view). E. Elytra and basal abdomen. F. Q. (M.) masasatoi Smetana, 2007, pronotum (arrows indicating punctures of the dorsal row). Abbreviation: Pf = posterior frontal puncture. Scale bars: A–B, D–E = 1 mm; C, F = 0.5 mm.

Fig. 6. A, F, H–I, K–L.Aedeagus, in situ. A, F, H, K. Ventral view (inset showing paired teeth). I, L. Lateral view. B–D. Median lobe. B. Ventral view. C–D. Lateral view. E, G, J, M. Underside of paramere. A–E. Malaisdius ruficeps (Scheerpeltz, 1965). F–G. M. smetanai gen. et sp. nov. H–J. Quedius (Microsaurus) piceolineatus Scheerpeltz, 1965. K–M. Q. (M.) masasatoi Smetana, 2007. Scale bars: A–D, F, H–I, K–L = 0.5 mm; E, G, J, M = 0.1 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.