Scaphisoma declivum Löbl, 2021

Löbl, Ivan, Leschen, Richard A. B. & Warner, William B., 2021, Scaphisomatini of Arizona (Coleoptera, Staphylinidae, Scaphidiinae) collected by V-Flight Intercept Traps, Revue suisse de Zoologie 128 (1), pp. 173-185 : 182-183

Scaphisoma declivum Löbl , sp. nov.

Figs 11-12

Material examined:

Holotype: MHNG (# MHNG-ENTO-86104); male; USA: AZ: Santa Cruz Co. Palo Prado Rd. , east side Santa Cruz R.; 31.531°, 111.016°; July 11-16, 2018; V-flight intercept trap; W.B. Warner.

Paratypes: MHNG, WBWC; 2 males, 4 females with the same data as the holotype ; – WBWC, MHNG, 8 males, 13 females, USA: AZ: Santa Cruz Co. Duquesne Rd. , 2.3 rd. Mi E jct. Hwy. 82; Santa Cruz R. ; 31.3757°, - 110.8406° Aug. 3-14, 2018; V-flight intercept trap; W.B. Warner

Etymology: The species epithet is a Latin adjective meaning inclined.

Diagnosis: The species is defined by the following characters in combination: body length about 1.70- 2.10 mm, body light reddish-brown, antennomere VI about 1.5 times as long as antennomere V and twice as long as antennomere IV, elytron with basal stria broadly separated from lateral stria, elytral disc with punctures well delimited, dense and fine, submesocoxal areas about as long as third of shortest intervals to metacoxae, abdominal microsculpture punctulate, aedeagus as Figs 11, 12 , symmetrical and narrow, median lobe shorter than basal bulb, strongly inflexed and tapering, with narrow dorsal bridge, parameres narrowed at middle section, internal sac membranous.

Description: Length 1.70-2.05 mm, width 1.16- 1.55 mm. Head, most of body and femora evenly light reddish-brown. Apex of abdomen, antennae, tibiae, and tarsi lighter. Antennomeres I to VI about as light as tarsi. Antennomere II about twice as long as antennomere III. Length/width ratios of antennomeres as: III 13/10: IV 23/8: V 34/10: VI 48/12: VII 52/16: VIII 42/13: IX 49/16: X 50/17: XI 65/16. Pronotum with lateral margins rounded, lateral margin carinae usually visible in dorsal view, discal punctation dense and fine, consisting of well delimited punctures. Tip of scutellum exposed. Elytra moderately narrowed apically, lateral margin rounded, lateral margin carina exposed in dorsal view, inner apical angle about in level with outer apical angle, sutural margin not raised, adsutural area flat, narrowed apically, with irregular, very fine puncture row; sutural striae curved at base and extended laterally to form basal striae reaching about mid-width of basal margin, discal punctation very fine near base, dense and fine on prevailing surface, punctures welldelimited, puncture intervals on apical half of disc about twice to as large as puncture diameters. Exposed tergites very finely punctate, with distinct punctulate microsculpture. Hypomeron smooth. Mesepimeron distinctly shorter than distance between its tip and mesocoxa. Metaventrite finely, very densely punctate, not microsculptured, flattened at middle. Submesocoxal lines convex, densely margined with punctures; submesocoxal area about 0.05-0.06 mm long, as third of shortest distance to metacoxa. Metanepiternum narrowed anteriad. Ventrite I with punctation similar as metaventrite, microsculpture punctulate, sometimes obsolete or hardly visible, submetaxocal lines convex, densely margined with punctures; submetacoxal area 0.06-0.08 mm long, about as fourth to third of shortest distance to apical margin. Following ventrites with conspicuous punctulate microsculpture. Male ventrite VI with small mesal process about 0.03 mm long. Male protarsomeres I to III distinctly widened, with tenant setae. Aedeagus ( Figs 11, 12 ) 0.68-0.75 mm long, strongly sclerotized.

Distribution: USA: Arizona.

Type locality: Arizona, Santa Cruz Co. Palo Prado Rd. , east side Santa Cruz R., 31.531°N, 111.016°W.

Remarks: The aedeagus of S. declivum is rather similar with that of S. carolinae Casey, 1893 and S. rubens Casey, 1893 , but the apical process of the median lobe is much wider and comparatively shorter, and the parameres are evenly arcuate in dorsal view. The species may be easily distinguished from S. carolinae by the larger and lighter body and the distinct mesepimera, and from S. rubens by the elytra with basal striae. The aedeagus of S. rubens ( Fig. 16 ) is distinctive in lateral view and illustrated for the first time in the present paper.

Figures

Figs 11-16. Aedeagi in Scaphisoma. (11-12) S. declivum Löbl, sp. nov., in dorsal and lateral views, scale = 0.1 mm. (13-14) S. desertorum Casey, in dorsal and lateral views, scale = 0.2 mm. (15) S. rufulum LeConte, in dorsal view, scale = 0.2 mm. (16) S. rubens Casey, in lateral view, internal sac extruded, scale = 0.1 mm.