Microscydmus (Opresus) misellus (LeConte, 1852)

Jałoszyński, Paweł, 2017, Status of Nearctic subgenera of Microscydmus revisited (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4358 (3) : -

Microscydmus (Opresus) misellus (LeConte, 1852) , comb. rest.

( Figs 1, 4 , 7, 10 , 13 )

Scydmaenus misellus LeConte, 1852: 155 .

Opresus misellus (LeConte) ; Casey, 1897: 495.

Microscydmus (s. str.) misellus (LeConte) ; Franz, 1985: 176.

Type material studied. Lectotype (here designated): sex unknown: seven labels ( Fig. 4 ): "J. LECONTE / COLLECTION" [white, printed], " S. misellus / Lec." [white, handwritten], " Microscydmus / misellus / Lec. / det.H.Franz" [white, handwritten and printed], "Opresus / det. W. Suter '77" [white with black margins, handwritten], " TYPE / LECONTE-MCZ" [pink, typed], " Type / 6235" [red, printed and handwritten], and small red circle ( MCZ).

Diagnosis. BL 0.80 mm; body light brown; anterior margin of frons in dorsal view subtriangular and rounded; antennomeres III–X transverse; punctures on head and pronotum very fine, inconspicuous, those on elytra slightly more distinct but only superficial and diffuse; pronotum about as long as broad; EI 1.46.

Description. Body of lectotype of unknown sex ( Fig. 1 ) moderately convex with slightly flattened elytral dorsum, elongate, with moderately long appendages, BL 0.80 mm; cuticle glossy, uniformly light brown; vestiture of setae and bristles slightly lighter than cuticle.

Head ( Figs 1 , 7, 10 ) subhexagonal, broadest at eyes, HL 0.13 mm, HW 0.19 mm; vertex and frons confluent, weakly convex; supraantennal tubercles feebly marked; eyes large, strongly convex and coarsely faceted. Punctures on vertex and frons fine and inconspicuous; setae short, sparse, suberect, tempora and genae with sparse bristles. Antennae ( Fig. 1 )) short, AnL 0.35 mm; scape and pedicel elongate, scape slightly longer than pedicel, antennomeres III–IX distinctly transverse, XI shorter than IX and X combined, about as long as broad.

Pronotum ( Figs 1 , 7 ) in dorsal view nearly round, broadest slightly in front of middle, PL 0.20 mm, PW 0.21 mm; anterior margin rounded, very indistinctly demarcated from lateral margins which are strongly rounded in anterior half and nearly straight in posterior third; posterior corners obtuse-angled and blunt; posterior margin shallowly bisinuate; four antebasal pits shallow and small but distinct, separated by subequal spaces, inner pair connected by shallow and diffuse transverse impression (poorly visible in Fig. 7 ). Punctures on pronotal disc as fine as those on frons and vertex; setae short and sparse, suberect, sides and lateroventral portions of hypomera sparsely covered with thick bristles.

Elytra ( Fig. 1 ) suboval and slightly flattened, broadest in front of middle, EL 0.48 mm, EW 0.33 mm, EI 1.46; basal impressions shallow but distinct, humeral calli elongate; apices separately rounded. Punctures on elytral disc slightly more distinct than those on head and pronotum but superficial and diffuse; setae sparse, short, suberect.

Hind wings not studied.

Legs moderately long and slender; unmodified.

Distribution. Georgia and Louisiana (according to Casey (1897)).

Remarks. The only available specimen is in a fragile condition and was not dissected to avoid further damage. Identifications and descriptions of new North American species must be based on direct comparisons with the lectotype of M. misellus , as the current diagnosis lacking genital characters may be ambiguous.

Lectotype designation. LeConte (1852) clearly stated that the type series was composed of two specimens; consequently, the specimen preserved at MCZ (illustrated in Fig. 1 and with labels as in Fig. 4 ) is a syntype. This specimen is here designated as lectotype for Scydmaenus misellus LeConte, 1852 .

Figures

FIGURES 1–6. Microscydmus (Opresus) misellus (LeConte) (1, 4); Delius robustulus Casey (2, 5); Neladius tenuis Casey (3, 6). Dorsalhabitus of lectotypes (1–3) and their historical sets of labels (4–6).

FIGURES 7–12. Microscydmus (Opresus) misellus (LeConte) (7, 10); Delius robustulus Casey (8, 11); Neladius tenuis Casey (9, 12). Head, pronotum and elytral bases in dorsal view (7–9); head, prothorax and anterior portion of pterothorax in ventral view (10–12). Abbreviations: abp, antebasal pit; bef, basal elytral fovea; bst, basisternal part of prosternum; hr, hypostomal ridge; hyr,hypomeral ridge; lss, lateral suture of submentum; nss, notosternal suture; pcr, procoxal rest.

FIGURES 13–15. Microscydmus (Opresus) misellus (LeConte) (13); Delius robustulus Casey (14); Neladius tenuis Casey (15); pterothorax and abdomen in ventral view. Abbreviations: msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; pcr, procoxal rest; pm, paramere; stVII–VIII, abdominal sternite VII–VIII.