Delius robustulus Casey

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

publication ID

publication LSID

persistent identifier

treatment provided by


scientific name

Delius robustulus Casey


Delius robustulus Casey   , stat. rest.

( Figs 2, 5 View FIGURES 1–6 , 8, 11 View FIGURES 7–12 , 14 View FIGURES 13–15 , 16–17 View FIGURES 16–19 )

Delius robustulus Casey, 1897: 497   .

Microcydmus (Delius) robustulus (Casey)   ; Franz, 1985: 176.

Type material studied. Lectotype (here designated): ♂: six labels ( Fig. 5 View FIGURES 1–6 ): "St. Vinc. / Penn." [white, printed], "CASEY / bequest / 1925" [white, printed], "10" [white, handwritten], " Delius   / robustulus   / Casey" [white, handwritten], " Delius   / robustulus Casey   / Holotypus / det.H.Franz" [white, handwritten and printed], "TYPE USNM / 49122" [red, printed and handwritten] (NMNH). Paralectotype: three labels: "St. Vinc. / Penn." [white, printed], "CASEY / bequest / 1925" [white, printed], "10" [white, handwritten], " robustulus   2 / PARATYPE USNM / 49122" [red, handwritten and printed] (NMNH).

Diagnosis. As in genus, vide supra.

Description. Body of male ( Fig. 2 View FIGURES 1–6 ) moderately convex with slightly flattened elytral dorsum, elongate, with moderately long appendages, BL 0.86–0.88 mm; cuticle glossy, uniformly light brown; vestiture of setae and bristles slightly lighter than cuticle.

Head ( Figs 2 View FIGURES 1–6 , 8, 11 View FIGURES 7–12 ) subhexagonal, broadest at eyes, HL 0.13 mm, HW 0.18 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 moderately dense, long bristles. Antennae ( Fig. 2 View FIGURES 1–6 ) 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 2 View FIGURES 1–6 , 8 View FIGURES 7–12 ) in dorsal view subtrapezoidal, broadest in anterior third, PL 0.23 mm, PW 0.23 mm; anterior margin rounded and confluent with lateral margins, which are strongly rounded in anterior half and weakly sinuate in posterior third; posterior corners obtuse-angled and blunt; posterior margin indistinctly bisinuate; four antebasal pits shallow and small, lateral pair obscured by bristles, inner pair connected by a short transverse groove (poorly visible in Fig. 8 View FIGURES 7–12 ) and separated much more narrowly than each inner and lateral pit. Punctures on pronotal disc as fine as those on frons and vertex; setae short and sparse, suberect, sides and lateroventral portions of hypomera densely covered with thick bristles.

Elytra ( Fig. 2 View FIGURES 1–6 ) suboval and slightly flattened, broadest in front of middle, EL 0.51–0.53 mm, EW 0.33–0.35 mm, EI 1.50–1.58; basal impressions shallow and short, humeri 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.

Aedeagus ( Figs 16–17 View FIGURES 16–19 ) stout, AeL 0.10 mm, thin-walled, median lobe symmetrical, with circular ventral diaphragm, endophallic structures asymmetrical, weakly sclerotized and relatively simple; parameres broadened in apical region and curved dorsally, each with two tiny subapical setae.

Distribution. Pennsylvania.

Lectotype designation. Casey (1897) mentioned two specimens, and despite Franz's interpretation of one of them as a holotype, they have a status of syntypes. Specimen illustrated in Fig. 2 View FIGURES 1–6 , with labels as in Fig. 5 View FIGURES 1–6 , is here designated as lectotype for Delius robustulus Casey, 1897   .














Delius robustulus Casey

Jałoszyński, Paweł 2017

(Delius) robustulus

Franz 1985: 176

Delius robustulus

Casey 1897: 497