Lathrobium (s.str.) ishiharai, Hayashi, 1994

Ryvkin, Alexandr B., 2011, On new and poorly known Lathrobium (s. str.) species from Siberia and the Russian Far East (Insecta: Coleoptera: Staphylinidae: Paederinae), Baltic Journal of Coleopterology 11 (2), pp. 135-170 : 155-157

Lathrobium (s.str.) ishiharai ursinum ssp.n.

( Figs. 15–18)

Material. RUSSIA: 1 male-HT( ZMMU): “ Amur Area, Mazanovskiy | District, Nora River mouth, [210 m a.s.l.,] mosses and | leaf litter on natural | levee and in flood-plain forest with | Alnus sp. , Salix spp. , Padus sp. , | ferns, [ Poaceae gen. spp., 2006. [E.M.]Veselova, [A.B.]Ryvkin [leg.] #139” [in Russian], “ HOLOTYPUS ”[my standard printed red label], “ Lathrobium HT | ishiharai ursinum ssp. n. | A.B.Ryvkin det. 2006” [my standard determinative label].—1 malePT[somewhat immature specimen with right elytron entirely soft]( AR): Amur Area, Selemdzhinskiy District, near border of Norskiy Nature Reserve, island on Selemdzha River near Dvadtsatikha cordon, leaf litter, mosses, drift in the heart of the island[: among Salix spp. , Populus sp. , Picea ajanensis , Abies nephrolepis ,

Ryvkin A.B.

sp., etc]. 06.08.2004. A.B.Ryvkin [leg.] #11[in Russian].—1 female-PT( AR): Amur Area, Mazanovskiy District, Nora River basin, Sorokavyorstnaya channel, Sosnovaya mountain, [215 m a.s.l.,] leaf litter and drift on channel bank under mountain slope with Carex spp. , Poaceae gen. spp., [ Alnus sp. , Padus sp. , Salix spp. , Swida alba ,] etc. 30.07.2006. E.M.Veselova, A.B.Ryvkin [leg.] #87 [in Russian].— 1 male-PT(AVSh): S Maritime Province, Lazovskiy Nature Reserve, 2 km W Lazo. 28.06.2007. A.Shavrin leg.—1 femalePT(AVSh): S Maritime Prov., Lazovskiy Nature Reserve, Lazo, Lazovka River valley. 26– 29.06.2007. A.Shavrin leg. The paratypes listed above are provided also with both “ PARATYPUS ” printed red label and my standard determinative label each.

Description. Body (in mature specimens) dark pitchy-brown to brownish-black; elytral suture and posterior margin narrowly and vaguely lightened, reddish-brown; antennae brown, mandibles dark brown, maxillar palpi and labrum yellowish-brown, legs brownish-yellow with bases of tibiae slightly darkened. Forebody distinctly, abdominal tergites fatty shining. Pubescence fairly short but dense, piceous with golden shine.

Length: 7.5–9.6 mm (the last value for the specimen with abdomen extended).

Head somewhat longer from neck to anterior margin of front than broad across basal 1/4 (79:75), nearly twice as broad as the neck constriction (75:39); posterior angles distinct, broad angularly rounded, posterior margin a bit emaginated in the middle, nearly straight; temples slightly convex, 2.2 to 2.5 times as long as eyes (43:19 to 42:17, view from above). Puncturation moderately deep, rather dense and more regular anterolaterally and near posterior angles, irregular and much sparser medially; average diameter of the coarsest punctures of the disk equal to 1/3 cross-section of antennal segment 2; wide interstices between median punctures 3 to 4 times as broad as diameter of punctures; puncturation of temples somewhat finer than that on the disk, not very dense; puncturation of underside fairly sparse and shallow. Fine and close cellular ground-sculpture well-developed throughout, somewhat finer on median area of disk; extremely fine and scatterred micropuncture is visible mainly on anterior parts. Antennae fairly long, scarsely reaching the basal margin of pronotum, with segments 2–10 elongated, inverted conical. Length/ width proportions of antennal segments 1–11 as 31/12: 15/9: 18/9: 16/9: 15/9: 15/9: 15/9: 14/9: 14/9: 14/8.5: 19/8.

Pronotum moderately convex, a little broader than head (79:75), by more than 1/4 longer than broad (100: 79 in holotype); lateral sides slightly convex (73:79:76); both anterior and posterior angles broadly rounded; very fine median longitudinal furrow well developed in basal 1/4–1/5, vaguely extending as a feeble stroke to the middle of length. Median longitudinal impunctate strip reaching or nearly reaching both anterior margin and posterior one, slightly raised in basal part, on average as broad as 1/12 maximum breadth of pronotum. Puncturation on each side of the median longitudinal smooth strip much more regular, evidently larger on average than that of the head with interstices between punctures evidently smaller than average diameter of punctures; some narrow longitudinal smooth areas situated on the disk laterally. The whole disk devoid of regular ground-sculpture, varnish shining.

Elytra moderately convex, a little longer than pronotum (107:100), somewhat longer than broad (107:93), moderately and uniformly dilated posteriorly (82:93) behind rounded but developed humeri. Suture a much shorter than pronotum (84:100), somewhat elevated throughout excluding the very base; flanked with a pair of narrow and shallow sutural impressions; humeral and lateral impressions absent; posterior margin very finely bordered throughout. Puncturation on average evidently smaller, somewhat denser and more regular than that of pronotum, average diameter of punctures on the disk a bit larger than that on the head. Very fine irregular microreticulation evident between punctures at high magnification. Wings normally developed.

Abdomen un ifor mly and weakly widen ed posteriorly, segments 6–7 slightly broader than

On new and poorly known Lathrobium (s.str.) species from Siberia and the Russian Far East ...

fore visible segments; fore abdominal tergites evidently flattened, preapical tergites somewhat more convex. Posterior margin of tergite 7 with evident white fringe. Puncturation of fore visible abdominal tergites very fine and fairly dense, somewhat sparser medially; tergite 3 medially punctured sparser than tergites 4–6; posterior margin of tergite 7, before the white fringe, with an evident band impunctate; median parts of tergites 8–9 punctated much sparser than those of preceding ones. Very fine and dense wavyreticular ground-sculpture well-developed throughout.

Male: Posterior margin of abdominal sternite 8 nearly straight, with neither conspicuous emarginations nor impressions (fig. 17); underside of the sternite punctured somewhat denser medioposteriorly; no conspicuous spiculiferous and setaceous structures are developed; aedeagus as in figs. 15–16, with operculum small, extremely feebly sclerotized.

Female: Posterior margin of abdominal tergite 8 nearly straight; abdominal sternite 8 with a bit asymmetric broad rounded posterior margin; structure of abdominal segments 9–10 as in fig. 18.

Etymology. The subspecific name is the Latin adjective “ursinum” (bear’s).

Diagnosis. In the shape of the aedeagus and male abdominal structure, the new taxon is very similar to Lathrobium ishiharai Hayashi, 1994 , the macropterous species of the monticola group (sensu Watanabe 2000 et al.), and can be distinguished from the nominate subspecies by the shorter elytra, the distal part of the aedeagus evidently bent towards the basal opening, and the absence of sclerotized nodule at the apex of the aedeagus. In the shape of the aedeagus, Lathrobium ishiharai ursinum ssp.n. is also closely related to species attributed by Watanabe (1999, 2005) to the pollens group ( L. pollens Sharp, 1889 , L. yosiianum Watanabe, 1999 , L. owaseanum Watanabe, 2005 , L. shotaroi Watanabe, 2005 , L. gomadanzanum Watanabe,

2005, L. hayashii Hayashi, 1999 , et al.) and differs from the latters by the longer elytra with humeral angles more prominent, the well-developed wings, the male abdominal sternites 7–8 without distinct impressions and emarginations, and the detailes of the aedeagus.