Eusphalerum thayeranum Zanetti, 2014

Zanetti, Adriano, 2014, Taxonomic revision of North American Eusphalerum Kraatz, 1857 (Coleoptera, Staphylinidae, Omaliinae), Insecta Mundi 2014 (379), pp. 1-80 : 44-45

Eusphalerum thayeranum Zanetti n. sp.

Material examined (93 specimens)

Holotype m 4 paratypes mm 2 paratypes ff British Columbia Garibaldi P.P., Cheakamus Lk. 3000 20.07.1973 leg. A. & Z. & D. Smetana (CNC)

Other paratypes. CANADA. Alberta 1 m Ponaka (2 mi. S), Battle R. 6.08.1976 leg. J.M. Campbell (CNC); 1 m Waterton Lks. NP, Crypt Lake Tr. 4500' 22.06.1980 leg. JM Campbell (CNC); 1 m Waterton N.P., Lineham Creek Tr. 5900 6500 3.08.1976 leg. J.M. Campbell (CNC); 4 mm 2 ff Waterton N.P., Rowe Creek 5460 2.08.1976 leg. J.M. Campbell (CNC); 4 ff Waterton N.P., Rowe Creek 5400' 4.08.1976 leg. JM Campbell (CNC); British Columbia 1 m Courtney, Forbidden Plateau near Courtney Lookout 25.07.1979 leg. I.M. Smith (CNC); 3 mm 4 ff Klimpton Cr., Kootenay N.P. 4000 21.07.1971 leg. J.M. & B.A. Campbell (CNC); 3 mm 6 ff Kootenay N.P., Kindersley Pass 7000 23.07.1971 leg. J.M. & B.A. Campbell (CNC); 10 mm 11 ff Manning Pr. Pk, Rhododendron Flats Rhododendron flowers 21.06.1988 leg. J.M. Campbell (CNC); 1 m Manning Prov. Park, Sumallo Grove (Hwy5a) 650 m 10.07.1988 leg. Burckhardt & Loebl (MHNG); 1 m 3 f Manning Prov. Pk., Sumallo Grove Cornus flower 21.06.1988 leg. J.M. Campbell (CNC); 10 mm 10 ff Mount Cain 27.07/ 10.08.1996 leg. Winchester (cZan); 3 mm Osoyoos grass clippings 24.06.1988 leg. J.M. Campbell (CNC); 2 mm 2 ff Silver Star Prov. Pk. 6200 ground squirrel burrows (1 spec.) 8.08.1973 leg. R.H. Parry (CNC); 1 m 1 f Squamish, Diamond Head Trail 3500 10.08.1953 leg. G.J. Spencer (CNC); 1 m 2 ff Squaw Valley, nr. Mabel Lake 5.08.1982 leg. R. Baranowski (MZLU); 3 mm 6 f Wells Gray Prov. Pk., Falls Ck 30.06.1988 leg. J.M. Campbell (CNC); 10 mm 10 ff Mt. Cain 50 o 13’N 126 o 21’W 13.07/ 27.07.1997 leg. Corkum (cZan). USA. Idaho 1 m Bonner Co Sandpoint 20.06.1971 leg. N. M. Downie (FMNH); Indiana 1 m Tippecanoe Co 15.05.1976 leg. N.M. Downie (FMNH) [doubtful record]; Maine (?). 1 m Bascea (??) 2000 m 18.07.19?? (interrogation marks in the label) leg. N. M. Downie (FMNH) [doubtful record]; Oregon 1 m Clackamas Co jct US26 Ore 35 (1.3 m E) 3900 ft on flowers Achlys triphylla 12.07.1975 leg. A. Newton and M. Thayer (FMNH); 1 m 1 f Clackamas Co jct US26 Ore 35 (1.3 m E) 3900 on flowers Lupinus 12.07.1975 leg. A. Newton and M. Thayer (FMNH); 5 mm 16 ff Clackamas Co Mt. Hood N.F., Still Creek Cmpg. 4000' 31.07.1979 leg. JM & BA Campbell (CNC); 1 m Wallawa Co Eagles Cap Prim. Area, Moccasin Lk. 7500' 29.07.1981 leg. JM Campbell (CNC); 1 f Mt. Hood, Timberline Lodge Rd. 4800' 29.07.1979 leg. JM & BA Campbell (CNC); Washington 2 mm Clallam Co Olympic N.P., Hurricane Ridge Rd 625 m mixed coniferous forest, on flowers Rubus parviflora 9.07.1988 leg. A. Newton and M. Thayer (FMNH); 2 mm 2 ff Clallam Co Olympic N.P., Lake Creek at Hurricane Ridge Rd., 625 m mixed conifer forest, on flowers Clintonia uniflora 9.07.1988 leg. A. Newton and M. Thayer (FMNH); 9 mm 11 ff Whatcom Co Mount Baker 29.07.1931 leg. M. Sanderson (KSEM); 3 mm 1 f Whatcom Co Mt. Baker 1500 m 19.06.1987 leg. W.M. Downie (FMNH).

Measurements. Head length: 0.20-0.25; head width: 0.42-0.55; pronotal length: 0.35-0.64; pronotal width: 0.42-0.70; elytral length: 0.85-1.12; elytral width: 0.79-1.03; length (clypeus to apex of elytra): 1.42-1.85; total length: 1.8-2.4.

Etymology. The species is dedicated to one of its collectors, Margaret K. Thayer, specialist of Staphylinidae Omaliinae , who has helped me greatly in the study of North American Eusphalerum .

Description. Habitus as in Fig. 126. Head, pronotum and elytra yellowish; abdomen dark brown, somewhat paler at apex (male) or entirely yellowish, very feebly darkened at apex (female); prosternum, metasternum, and legs yellowish; antennae yellowish, more or less darkened from antennomere 7, often entirely yellowish.

Head with prominent eyes; postocular carina well marked; temples short, convergent caudad. Medial margin of eyes with microsculpture formed by slightly lengthened meshes; postantennal depression large, not very deep, confluent with the small, rounded tentorial pits forming 2 superficial longitudinal depressions in front of ocelli; punctation very superficial and sparse; ground with isodiametric microsculpture; neck scarcely separated from head. Antennae rather short, antennomere 1 and 2 ovoid, 3 elongate, twice as long as wide, 4 and 5 longer than wide, 6 subquadrate, 7-10 transverse, 10 less than twice as wide as long, 11 twice as long as wide, cylindrical in the proximal part, conical at apex.

Pronotum not very convex, without impressions, transverse (ratio width/length = 1.4-1.5), widest slightly in front of middle, anterior margin slightly narrower than posterior, lateral margins rounded, posterior angles scarcely obtuse and well marked, punctation very sparse and superficial, ground with isodiametric microsculpture, pubescence extremely short, scarcely visible, depressions near posterior angles not much marked, extended anteriad in front of middle.

Elytra scarcely elongate (ratio length from scutellum to apex / combined width of elytra = 1.0), truncate at apex in both sexes, clearely widened toward apex, punctation much stronger than on pronotum, irregular and scarcely confluent, ground glossy, pubescence extremely short and scarcely visible.

Abdomen rather glossy, microsculpture superficial with decumbent pubescence.

Tibiae straight in both sexes, not modified, tarsomere 5 of posterior tarsi as long as 1-4 together.

Aedeagus as in Fig. 127, internal sac with 2 long spines.

Accessory sclerites of female as in Fig. 128, spermatheca as in Fig. 129.

Comparative notes. Eusphalerum thayeranum is very similar to E. fenyesi in external characters, but metasternum is usually yellowish instead of brownish. The presence of 2 long spines in the internal sac of the aedeagus is very characteristic; those of E. margaretae are much shorter.

Distribution. CANADA: Alberta, British Columbia; UNITED STATES: Idaho, Indiana, Oregon, Washington (Map 3). The record from Indiana (Tippecanoe) is questionable, as it is outside the main geographical range of the species and the area does not possess the normal ecological conditions in which E. thayeranum lives. Its collector, N. M. Downie, lived and collected for decades in Tippecanoe Co., but also collected extensively in the western USA, so a label mixup may have occurred. The Maine (?) record is likewise doubtful.

Natural history. The species was collected in a wide altitudinal range, between 600 and 2300 m. Reported host plants: Rhododendron sp. (Ericaceae) , Cornus sp. (Cornaceae) , Achlys triphylla (Sm.) DC. (Berberidaceae) , Lupinus sp. (Fabaceae) , Rubus parviflorus Nutt. (Rosaceae) , Clintonia uniflora (Menzies ex Schult. & Schult.f.) Kunth ( Liliaceae ). The only macrohabitat reported on the labels is mixed conifer forest. Most captures between June and August.