Neladius tenuis Casey

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

Neladius tenuis Casey , stat. rest.

( Figs 3, 6 , 9, 12 , 15 , 18–19 )

Neladius tenuis Casey, 1897: 499 .

Microcydmus (Delius) tenuis (Casey) ; Franz, 1985: 176. Microscydmus (Neladius) tenuis (Casey) ; O'Keefe: 264.

Type material studied. Lectotype (here designated): ♂: six labels ( Fig. 6 ): " CASEY / bequest / 1925" [white, printed], "St. Vinc / Penn." [white, printed], "48" [white, handwritten], " Neladius / tenuis / Casey" [white, handwritten], " Delius / tenuis (Casey) / Holotypus / det.H.Franz" [white, handwritten and printed], " TYPE USNM / 49123" [red, printed and handwritten] ( NMNH). Paralectotype: ♂, four labels: " CASEY / bequest / 1925" [white, printed], "St. Vinc / Penn." [white, printed], "48" [white, handwritten], "tenuis- 2 / PARATYPE USNM / 49123" [red, handwritten and printed] ( NMNH).

Diagnosis. As in genus, vide supra.

Description. Body of male ( Fig. 3 ) moderately convex, elongate, with moderately long appendages, BL 0.94– 1.00 mm; cuticle glossy, uniformly light brown; vestiture of setae slightly lighter than cuticle.

Head ( Figs 3 , 9, 12 ) subtrapezoidal, broadest at eyes, HL 0.15–0.16 mm, HW 0.19–0.2 mm; vertex and frons confluent, weakly convex; supraantennal tubercles feebly marked; tempora in anterior half nearly parallel; eyes small, weakly convex and finely faceted. Punctures on vertex and frons fine and inconspicuous; setae short, sparse, suberect. Antennae ( Fig. 3 ) short, AnL 0.38 mm; scape and pedicel elongate, scape slightly longer than pedicel, antennomeres III–VII each about as long as broad, VII distinctly larger than VIII, VIII–X transverse, XI shorter than IX and X combined, about as long as broad.

Pronotum ( Figs 3 , 9 ) in dorsal view oval, broadest in anterior third, PL 0.25 mm, PW 0.23 mm; anterior margin rounded and confluent with lateral margins, which are strongly rounded in anterior half and nearly straight in posterior third, where they are strongly convergent; posterior corners strongly obtuse-angled and blunt; posterior margin rounded. Punctures on pronotal disc as fine as those on frons and vertex; setae short and sparse, suberect.

Elytra ( Fig. 3 ) suboval, broadest in anterior third, EL 0.53–0.60 mm, EW 0.33–0.35 mm, EI 1.50–1.85; basal impressions and humeral calli absent; apices separately rounded. Punctures on elytral disc as inconspicuous as those on head and pronotum; setae sparse, short, suberect.

Hind wings absent.

Legs moderately long and slender; unmodified.

Aedeagus ( Figs 18–19 ) elongate, AeL 0.18 mm, thin-walled, with symmetrical median lobe and strongly asymmetrical, darkly sclerotized and complicated endophallic structures; parameres strongly broadened distally and in apical region curved mesodorsally, each with one long subapical seta and one or two tiny apical setae.

Distribution. Pennsylvania.

Lectotype designation. Casey (1897) mentioned a male and a presumable female in his description. The male was identified by him on the basis of a tip of the aedeagus protruding from the genital opening, and this specimen, illustrated in Fig. 3 and with labels as in Fig. 6 is here designated as lectotype of Neladius tenuis Casey, 1897 . The other specimen turned out to be a male.

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.

FIGURES 16–19. Delius robustulus Casey (16–17); Neladius tenuis Casey (18–19). Aedeagus in ventral (16, 18) and lateral (17, 19) views.