Phlaeopterus czerskyi ( Shavrin, 2001 ) Shavrin, 2001

Mullen, Logan, 2015, Phlaeopterus Motschulsky, 1853 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini) — a new genus for the Palaearctic: new combination, Zootaxa 4028 (1), pp. 121-128 : 123-127

Phlaeopterus czerskyi ( Shavrin, 2001) comb. nov.

( Figs. 1–12 )

Lesteva czerskyi Shavrin, 2001: 190

Type material examined. Holotype of Lesteva czerskyi Shavrin, 2000 ♂: ‘ 14.VI. [19]96 [printed on the side] | Хамар-Дабан [Khamar-Daban Mts.] | Комаринский [Komarinskiy] | xp. [Mt.] h=1900 | Øàâðèí À. [Shavrin A. leg.]’, ‘ Holotype | Lesteva | czerskyi | Shavrin A. 2000’ <red printed label> ( ZIN). The holotype was collected in upper flow of Slyudyanka River (Irkutsk Area, Slyudyanskiy District, Khamar-Daban Mts., Komarinskiy Mt.; 51º51' N, 103º61' E). Paratype of Lesteva czerskyi Shavrin, 2000 ♀: ‘Хамар-Дабан [Khamar-Daban Mts.] | ср. т. Бабхи [middle flow of Babkha River] [51º46' N, 103º95' E] | 8–14.V.1999 | Шаврин А. [Shavrin A. leg.]’, ‘ Paratype | Lesteva | czerskyi | Shavrin A. 2000’ <red printed label> (cS).

Additional material. 1 ♀: E Siberia, Khamar-Daban Mts., upper of Babkha River, Babkha mountain. [51º42' N, 103º.89' E] h= 1600 m. 27.06.2006. Shavrin A. leg. (cS); 1 ♂: East Siberia, Khamar-Daban Mts., middle flow of Babkha River. [51º47' N, 103º96' E; h= 500 m]. 27.06.2006. Shavrin A. leg. (cS).

Redescription. Measurements (n=4): Maximum width of head including eyes: 0.74–0.75; length of head (from base of labrum to neck constriction along the head midline): 0.50–0.60; length of antenna: 1.50; longitudinal length of eye: 0.20–0.21; length of temple (from posterior margin of eye to neck constriction): 0.50–0.60; length of pronotum: 0.90–1.01; maximal width of pronotum: 1.25–1.40; minimal width of pronotum at the base: 0.85; length/width of segment 3 of maxillary palpi: 0.075 / 0.050; length/width of segments 4 of maxillary palpi: 0.175 / 0.05; sutural length of elytra (length of elytra from apex of scutellum to posterior margin of sutural angle): 1.25– 1.40; maximal width of elytra: 1.55–1.65; width of segment IV of abdomen: 1.55–1.65; length of hind tarsus (without length of tarsal claws): 0.45; length of segment 5 of metatarsus (without length of tarsal claws): 0.125; length of aedeagus: 0.56–0.57; body length: 4.00 (holotype)–4.30.

Forebody reddish brown (sometimes head slightly darker, brown with lateral margins of pronotum in posterior third and epicranial borders of head lighter, yellowish brown); abdomen reddish brown to black; clypeus and legs reddish brown to yellowish brown; antennomeres IV–IX and ocelli brown; antennal segments I–III and maxillary palpi yellow (sometimes segment IV of maxillary palpi darker, yellowish brown). Punctation of head dense, punctures deep and coarse, separated by one puncture diameter; punctation on temples and near neck smaller and denser, separated by one or two puncture diameters; pronotal punctures coarser than on head, on disc separated by one or two puncture diameters; scutellum with fine dense punctures; punctation of elytra irregular, punctures large and densely distributed, separated by one or two puncture diameters; punctation of abdominal tergites regular, fine and dense; surface of abdominal tergite IV slightly rugose between fine indistinct punctures.. Body without microsculpture, glossy. Pubescence of forebody decumbent, long, yellow; pubescence of tibiae dense and long; pubescence of abdomen short, yellow. Habitus as in Fig. 1 .

Head 1.6–1.8 times as wide as long, with prominent small eyes and short temples; eyes four times as long as temples. Vertex convex; surface in front of ocelli without longitudinal furrows, but with deeply impressed anteocellar foveae (two small impressions between anterior margins of eyes). Ocelli large, as large as diameter of two nearest punctures together; distance between ocelli subequal to distance between ocellus and posterior margin of eye. Neck (nuchal) constriction very smooth, vaguely marked. Labrum as in Fig. 3 . Mandibulae as in Fig. 4 . Labium as in Fig. 5 . Mentum as in Fig. 6 . Maxillary palpus as in Fig. 7 . Antennae relatively short, reaching shoulders of elytra; all antennomeres elongate, with lengths × widths: 1: 0.20 × 0.075; 2: 0.15 × 0.045; 3: 0.15 × 0.057; 4: 0.125 × 0.074; 5–6: 0.115 × 0.074; 7–8: 0.104 × 0.074; 9–10: 0.104 × 0.087; 11: 0.225 × 0.10.

Pronotum transverse (width/length ratio: 1.38), very convex, 1.6–1.8 times wider than head, widest near middle, strongly narrowed from widest point to base and apex, with deep long lateral impressions, hind angles about 90º; both lateral margins crenulate, strongly behind widest point, transitioning gradually to indistinct near base.

Scutellum large, subtriangular, with rounded apex.

Elytra moderately short and wide (width/length ratio: 1.2 on average), wider than maximal width of pronotum (maximal width of elytra/maximal width of pronotum ratio: 1.2 on average), posterior angles broadly rounded, hind margins of elytra obliquely truncate towards the suture. Wings reduced to short lobes.

Apical part of protibiae and inner and outer parts of meso- and metatibiae with several small long spines between setae. Metatarsomere 1 slightly shorter than apical metatarsomere; metatarsomere 5 equal to combined length of 3–4.

Abdomen very convex, slightly wider than elytra; abdominal tergites without wing-folding patches (tomentose spots) or palisade fringe on tergite VII.

Male. Pronotum slightly narrower; lateral tooth in middle of pronotum smoother, not well defined. First four protarsomeres weakly dilated, with longer and thicker ventral setae. Abdominal sternite VIII ( Fig. 8 ) and tergite VIII ( Fig. 9 ) with weakly emarginate posterior margin. Aedeagus ( Fig. 10 ) wide and short, gradually tapering towards apex; parameres wide, exceeding apex of aedeagus, slightly curved medially. Aedeagus laterally as in Fig. 11 .

Female. Pronotum distinctly transverse, with well defined lateral tooth at middle. Protarsomeres not dilated, without longer and thicker ventral setae. Abdominal sternite VIII and tergite VIII without emargination, straight apically.

Comparative notes. Phlaeopterus czerskyi specimens were compared to specimens of all described (as well as some undescribed) North American Phlaeopterus species by the second author. Phlaeopterus czerskyi can easily be distinguished from all other known congeners by the crenulate sides of the pronotum, which are not present in any other species of the genus. It most closely resambles the Nearctic P. lagrandeuri Hatch, 1957 , known from Canada and the USA, but can be distinguished from P. lagrandeuri by the head with anteocellar foveae more deeply impressed, pronotum and elytra with punctation coarser and deeper, metatrochanter lacking a large tooth on the apical margin, elytra shorter (see previous paragraph) and wider, and heavily sclerotized aedeagus with apex of median lobe more acute.

Using the key to the Nearctic Anthophagini of Newton et al. (2000), the most recent, authoritative, and comprehensive keys to the North American staphylinid genera, P. czerskyi keys to Phlaeopterus rather than Lesteva by its pronotum shape (not cordate and with explanate edges and lateral impressions), and by its head with neck (nuchal) constriction very smooth, vaguely marked. However, the exceptionally short elytra of P. czerskyi do not match the diagnosis of Phlaeopterus given by Newton et al. (2000). The ratio of elytra to pronotum length is used in the key of Newton et al. (2000) to differentiate Phlaeopterus from the genus Unamis : “elytral length more than 2, usually more than 2.2, times that of pronotum” for Phlaeopterus and “elytral length seldom more than 2 times that of pronotum” for Unamis . The elytra of P. czerskyi are less than twice as long as the pronotum, the shortest of any Phlaeopterus species. Nonetheless, P. czerskyi matches the diagnosis of Phlaeopterus of Newton et al. (2000) in all other characters, as well as the revised diagnosis of Phlaeopterus given above.

Bionomics. This species was collected in alpine and forest zones of the Khamar-Daban Mts. ( Fig. 12 ), in wet moss on the banks of small streams ( Fig. 2 ) at altitudes from 900 to 1900 m.

Nearctic Phlaeopterus species have been collected from sea level to 3500 m elevation, and are found on the surface of alpine snowfields, as well as under rocks and in moss at the edges of permanent or long lasting alpine snowfields and cold, cascading streams and waterfalls. Adults of Nearctic Phlaeopterus have been observed foraging on arthropod fallout (mostly flying insects, windblown from lower altitudes and often lethargic or frozen) on the surface of alpine snowfields (at night at lower latitudes but during the day in Alaska), and this feeding strategy is likely widely used in the genus.

Figures

FIGURE 12. Distribution of Phlaeopterus czerskyi (Shavrin, 2001).

FIGURES 1 – 2. Habitus, female (Fig. 1) and habitat (Fig. 2) in upper of Babkha River (Eastern Siberia, Khamar-Daban Mts.) of Phlaeopterus czerskyi (Shavrin, 2001). Scale bar: 1.0 mm.

FIGURES 3 – 9. Phlaeopterus czerskyi (Shavrin, 2001): 3 — labrum (dorsal view), 4 — left and right mandibles (dorsal view), 5 — labium (dorsal view), 6 — mentum (dorsal view), 7 — right maxilla (dorsal view), 8 — male abdominal sternite VIII (dorsal view), 9 — male abdominal tergite VIII (dorsal view). Scale bar: 0.1 mm.

FIGURES 10 – 11. Aedeagus of Phlaeopterus czerskyi (Shavrin, 2001): 10 — parameral view, 11 — lateral view. Scale bar: 0.1 mm.