Cephennium gilberti Hopp & Caterino, 2009

Hopp, Katie & Caterino, Michael, 2009, Seven new species of Cephennium Müller & Kunze (Coleoptera, Staphylinidae, Scydmaeninae, Cephenniini) from California with a key to native North American species, ZooKeys 24 (24), pp. 31-54 : 45-46

Cephennium gilberti Hopp & Caterino , sp. n.

urn:lsid:zoobank.org:act:307DD4D1-D511-447D-AFF4-2258EE6DFC10

Figs 1F, 2F, 3F, 6

Type Material. Holotype (unknown sex): “CALIF: Kern Co.; 5 mi. E Glenville [sic] [̴ 35.7486°N, 118.5805°W]; Alta Sierra Camp; III-12-1979; A.J. Gilbert ”/ “Berlesed;

Oak; Litter” ( CSCA). We did not risk dissecting the type to determine sex due to its uniqueness and minute size .

Etymology. We name this species in honor of Dr. Art Gilbert, collector of the unique specimens of two of the species described herein, including this one.

Diagnosis. This species can be distinguished from its California congeners by the character combination of the eyes absent, humeral angle of the elytron raised, dorsally flattened and apically rounded ( Fig. 3F ), scutellum with two setae ( Fig. 3F ), and the mesosternal keel weakly divergent at the apex ( Fig. 2F ). Th is species most closely resembles C. grandarboreum , but can be distinguished from it by its smaller size (0.646 mm long), more elongate and slender body (Fig. 1F), the posterior angles of the pronotum being sharper in C. gilberti (Fig. 1F), and the mesosternal keel more weakly divergent at the apex with the apex approximately only 2× as wide as the widest point anterior to the apex ( Fig. 2F ), as opposed to the apex strongly divergent and nearly 2.4× as wide as the widest point anterior to the apex as in C. grandarboreum ( Fig. 2D ). C. gilberti can be separated from C. anophthalmicum , C. urbanum and C. aridum by the humeral angle of the elytron, which projects laterally to a point in these species ( Fig. 3A , G-H). Finally, it can be distinguished from C. celsifrons , C. mariposae and C. aridum by the presence of ommatidia in these species ( Fig. 4A , C-D).

Description (sex unknown). Length: 0.646 mm; pronotal width: 0.228 mm; elytral width: 0.266 mm. Body elongate, slender, weakly convex, amber yellow, evenly moderately pubescent, pubescence golden, slender, moderate in length (Fig. 1F). Head small, deflexed, sparsely pubescent; frons flat; eyes absent. Antenna setose, antennomeres I and II longer than broad, antennomeres III-VI quadrate and smaller than antennomeres II and VII, antennomere VIII smaller than antennomeres VII and IX, antennomeres IX-XI gradually clavate forming a loose club. Pronotum moderately pubescent, broadest between middle and anterior third, disc very convex medially and weakly flattened near each posterior angle; anterior margin not visible from above; anterior and posterior margin lacking marginal bead; marginal bead complete laterally, gradually widening towards base; lateral edge broadly rounded to posterior third, then slightly sinuate to base (Fig. 1F). Hypomeron smooth, sparsely setose towards upper quarter and along outside (lateral) edge, hypomeral bead anterolaterad procoxae sinuate. Prosternum with prominent, bluntly triangular nodules anterolaterad procoxal cavities ( Fig. 2F ). Elytra impunctate, as pubescent as pronotum, covering all abdominal segments, weakly truncate at apex; elytral suture flat; elytral striae absent; basomedial fovea present on each elytron, fovea large, with moderately dense inwardly directed setae (Figs. 1F, 3F). Humeral angles of elytron raised, dorsal plateau apically rounded, slender, barely reaching beyond anterior portion of the elytral fovae ( Fig. 3F ). Scutellum roundly triangular, with two short setae, one on each side of the midline ( Fig. 3F ). Mesosternal keel setose with scalelike microsculpture over most of length, abruptly smooth near meso-metasternal junction, apex weakly divergent, angulate ( Fig. 2F ). Metathoracic wings vestigial. Femora strongly clavate in distal half, tibiae expanded and becoming more densely setose towards distal half. Six visible abdominal sternites (fusion between ventrites V and VI not evident).

Biology. Th is species has been collected only from berlesed oak litter.

Distribution. This species is known from a single locality five miles east of Glennville, at about 1800m in the southern Sierra Nevada of Kern County, CA (Fig. 6).

Figures

Figure 2. A–H Mesosternal keel SEMs A Cephennium anophthalmicum Brendel B Cephennium celsifrons Hopp & Caterino C Cephennium mariposae Hopp & Caterino D Cephennium grandarboreum Hopp & Caterino E Cephennium canestroi Hopp & Caterino F Cephennium gilberti Hopp & Caterino G Cephennium urbanum Hopp & Caterino H Cephennium aridum Hopp & Caterino.

Figure 3. A–H Base of left elytron A Cephennium anophthalmicum Brendel B Cephennium celsifrons Hopp & Caterino C Cephennium mariposae Hopp & Caterino D Cephennium grandarboreum Hopp & Caterino E Cephennium canestroi Hopp & Caterino F Cephennium gilberti Hopp & Caterino G Cephennium urbanum Hopp & Caterino H Cephennium aridum Hopp & Caterino.

Figure 4. A–D Characters on the head, including number of ommatidia and male frons A–B Cephennium celsifrons Hopp & Caterino C Cephennium mariposae Hopp & Caterino D Cephennium aridum Hopp & Caterino.