Lathrobium (Abletobium) shermani Fall, 1917

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) shermani Fall, 1917

Lathrobium shermani Fall, 1917: 164.

Type material.

Holotype ♂ (MCZ): "[Handwritten] Grandfather Mt Early Sep 1915 N.C. 4000 to 5000 ft. / ♂ / FSherman Collector / H. C. FALL COLLECTION / TYPE [handwritten] Lathrobium shermani / [red] M. C. Z. Type 24086."

Other material.

USA: Virginia: Patrick Co.: Stuart (36.7004, -80.2622), 12 Aug-10 Nov 2022, K. Ivanov, J. Means, L. Hightower (5 CUAC and VMNH) .

Diagnosis.

Lathrobium shermani is similar in appearance to L. hardeni , L. lapidum , and L. thompsonorum , all of which have combs of black setae on male sternite VIII. However, those species all have multiple combs, and the combs are continuous across the midline. They also differ in the shape and spines of the aedeagus. Females of L. shermani can be distinguished from L. hardeni by the lack of a subgenital plate, and from L. thompsonorum and L. lapidum by the pubescent gonocoxites.

Description.

We present descriptions and illustrations of the male and female genitalia, which were missing from the original description.

Body length 6 mm; body coloration pale red. Head wider than pronotum; eyes reduced to small white membranes without ommatidia; gular sutures parallel and widely separate; antennomeres V-VII 1.8 × longer than wide. Elytra shorter than pronotum.

♂: Type specimen differs from specimens collected in Virginia in the number of thick black setae on sternite VIII: type has ~ 8 per comb whereas Virginia specimens have five. Aedeagus large, 1.4 mm long; ventral process long, broad, and bent ventrally in lateral view (Fig. 20D, E ); lightly sclerotized median lobe protrudes beyond ventral process in lateral view; dorsal plate short and diamond-shaped; internal sac with four spines, major spine wide and 1/2 as long as ventral process, other three spines shorter than dorsal plate.

♀: Sternite VIII with a shallow, curved notch at apex (Fig. 20B ); paraprocts undivided anteriorly, apices approximately equal in length with basal portion; proctiger conical; sternum IX with valvifers and coxites fused, setose with fine pubescence on lower 2/3 (Fig. 20C ); subgenital plate absent.

Distribution.

USA: NC, VA.

Remarks.

Lathrobium shermani was previously known from only the holotype. Recently, additional specimens were collected in buried pipe traps in Stuart County, Virginia (Fig. 18 ). Fall (1917) did not state the method used to collect the holotype, but several attempts by the authors to recollect it at the type locality via litter sifting failed. In their checklist of Canadian beetles, Bousquet et al. (2013) listed L. shermani as occurring in Ontario, but this was due to a misidentification of L. pallecens . Lathrobium shermani is restricted to the southeastern USA.

Figures

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

Figures 19, 20. Lathrobium terminalia A female terminalia B male sternite VIII C aedeagus in ventral view D aedeagus in lateral view. 19 L. pallescens 20 L. shermani. Scale bars: 1 mm.