Lathrobium (Abletobium) solum Haberski & Caterino, 2024

Haberski, Adam & Caterino, Michael S., 2024, A review of Nearctic Lathrobium (Coleoptera, Staphylinidae), with revision and descriptions of new flightless species from the mountains of the southeastern U. S., ZooKeys 1198, pp. 193-277 : 193

Lathrobium (Abletobium) solum Haberski & Caterino sp. nov.

Type material.

Holotype ♂ (FMNH): "USA: Virginia: Botetourt Co., Jefferson NF, 0.25mi NW Blackhorse Gap parking, 37.42796N, 79.7558W, 2425ft., 24.May-19.July-2019, C.W Harden, Buried pipe trap baited with cheese, in gravelly soil, deciduous wooded rocky gully. BHG-02" / "CLEMSON ENT [QR CODE] CUAC000185155". Paratypes (6, VMNH, CUAC, FMNH): 6: same data as holotype (CUAC000185154, CUAC000177139, CUAC000177140, CUAC000177141, CUAC000177142, CUAC000177143).

Diagnosis.

Can be distinguished from all other microphthalmous Lathrobium , except L. absconditum , by its large size and unadorned male sternite VIII. It differs from L. absconditum in its transverse middle antennomeres and widely separate gular sutures but is most easily recognized by the aedeagus. Lathrobium solum has a distinct stirrup-shaped major spine in the internal sac, and the ventral process reaches the dorsal plate in lateral view, unlike in L. absconditum (Fig. 21C ).

Description.

Habitus (Fig. 21A ). Large species, total body length ~ 9 mm long, FL 3.5 mm long. Coloration: body and appendages pale reddish, distal segments of antennae lighter.

Similar to L. hardeni , except gular sutures straight and widely separated, 1/8 width of head but narrowing slightly posteriorly. Eyes reduced to small white membranes without ommatidia, occupying 1/10 lateral width of head. Antennomeres II-IV elongate, gradually widening so that antennomeres V-IX are as long as wide. Pronotum without a visible line at midline; interstices shiny with no microsculpture. Posterior margin more sinuate.

♂: Posterior margin of sternite VIII with a broad, shallow emargination (Fig. 21B ). Aedeagus 1.5 mm long; ventral process long, reaches dorsal plate, apex produced in an asymmetrical trunk (Fig. 21C, D ); dorsal plate short and diamond-shaped; internal sac with five more-or-less symmetrical spines, two largest spines connected by a thin stirrup.

♀: Female unknown.

Etymology.

The specific name is a play on words. In Latin Lathrobium solum can mean soil but also “lonely.” This species is hypogean, and the males are alone until a female is found.

Distribution and ecology.

Lathrobium solum is known only from the type locality in Botetourt County, Virginia (Fig. 18 ), where it was collected from a rocky gully in deciduous forest. All specimens were collected with buried pipe traps, suggesting they are hypogean. Collected May-July.

Figures

Figure 18. Distribution of Lathrobium lapidum (star), L. shermani (triangle), L. solum (square), L. thompsonorum (circle)

Figure 21. Lathrobium solum A habitus B male sternite VIII C aedeagus in ventral view D aedeagus in lateral view. Scale bars: 1 mm.