Lathrobium (Lathrobioma) scolopaceum (Casey, 1905)

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 (Lathrobioma) scolopaceum (Casey, 1905)

Lathrobioma scolopacea Casey, 1905: 103.

Lathrobium (Lathrobioma) scolopaceum : Bernhauer and Schubert 1912: 267.

Lathrobioma dakotana Casey, 1905: 100. New synonym.

Lathrobium (Lathrobioma) dakotanum : Bernhauer and Schubert 1912: 258.

Lathrobioma virginica Casey, 1905: 99. New synonym.

Lathrobium (Lathrobioma) virginicum : Bernhauer and Schubert 1912: 269.

Lathrobioma inops Casey, 1885; Casey 1905: 103. New synonym.

Lathrobium (Lathrobioma) inops : Blackwelder 1939, 108.

Type material.

Lectotype, Lathrobioma scolopacea Casey, herein designated (USNM): "B MASS / CASEY bequest 1925 / [red] TYPE USNM 38143 / [handwritten] Lathrobioma scolopacea / Lectotype Lathrobioma scolopacea Casey Desg. Haberski & Caterino." Lectotype, Lathrobioma dakotana Casey, herein designated (USNM): "[handwritten] Bismarck Dak / CASEY bequest 1925 / [red] TYPE USNM 38136 / [handwritten] Lathrobioma dakotana / Lectotype Lathrobioma dakotana Casey Desg. Haberski & Caterino." Lectotype, Lathrobioma virginica Casey, herein designated (USNM): "Grafton WV / CASEY bequest 1925 / [red] TYPE USNM 38139 / Lectotype Lathrobioma virginica Casey Desg. Haberski & Caterino." Lectotype, Lathrobioma inops Casey, herein designated (USNM): "L.Sup / ♂ / CASEY bequest 1925 / [red] TYPE USNM 38144 / Lectotype Lathrobioma inops Casey Desg. Haberski & Caterino."

Other material.

Canada: Ontario: ' L. Sup’ (1, USNM) . USA: Massachusetts: ‘Mass’ (2, USNM); Middlesex Co.: Framingham, 1944, C. A. Frost (1, MCZ) . Maine: Knox Co.: Isle-au-haut, Aug 1905 (1, MCZ) . New Hampshire: Grafton Co.: Downes Brook, Potash Mountain , 05 Jun 2021, A. Haberski (2, CUAC); Grafton Co. : Mount Lafayette , 04 Jun 2012, A. Haberski (1, CUAC); Strafford Co. : Spruce Hole Conservation Area , D. S. Chandler (1, UNHC); Grafton Co. : Hubbard Brook Experimental Forest , D. S. Chandler (1, UNH) .

Diagnosis.

Females of L. scolopaceum are readily distinguished from all other Lathrobioma by their divided paraprocts. Males can be distinguished by their uniquely shaped aedeagus, which has a ventrally projected apex of the ventral process.

Description.

Body length 6 mm; coloration reddish, appendages lighter. Gular sutures arcuate; maxillary palpomere III> 0.4 × as wide as long; antennomeres V-VII as long as wide. Elytra at least as long as pronotum, sometimes longer and wider. Females with paraprocts divided; sternite VIII weakly oblong. Characteristic aedeagus as in Fig. 32 .

Distribution.

Canada: ON, NB, NS, QC ( Bousquet et al. 2013). USA: IA, MA, ME, NH, ND, RI, VA, WV ( Newton 2022).

Remarks.

We reduce Lathrobium dakotanum , Lathrobium virginicum , and Lathrobium inops to synonymy with Lathrobium scolopaceum because the distinguishing characters given by Casey (1905) were inaccurate. Lathrobium dakotanum and L. virginicum were each described from a single female and differentiated from L. scolopaceum based on their elytra being at least equal in length to the pronotum, as opposed to "much shorter" ( Casey 1905). We measured the specimens in Casey’s collection and found that the elytra of L. scolopaceum were 1.1 × longer the pronotum, approximately the same as that of L. dakotanum and L. virginicum .

Lathrobium virginicum was further differentiated by having a head as wide as its elytra, as opposed to narrower in L. scolopaceum , L. dakotanum , and L. inops . Upon measuring, we found all four species have a head wider than their pronotum.

Lathrobium inops was distinguished as being larger and more slender than L. scolopaceum (Casey, 1905), but this was not the case.

The genitalia are identical in all four species.

Figures

Figures 29 - 34. Lathrobium terminalia A female terminalia B male sternite VIII C aedeagus in ventral view D Aedeagus in lateral view. 29 L. divisum 30 L. nanulum 31 L. othioides 32 L. scolopaceum 33 L. tenue 34 L. amplipenne. Scale bars: 1 mm.