Lathrobium ishiharai, Hayashi, 1994

Ryvkin, Alexandr B., 2014, Notes On Distribution And Taxonomy Of Some Far Eastern Staphylinidae (Coleoptera), Acta Biologica Universitatis Daugavpiliensis 14 (2), pp. 177-185 : 183

The ishiharai group

Since Lathrobium (s. str.) ishiharai Hayashi, 1994 and L. (s. str.) ursinum Ryvkin, 2011 stat. nov. constitute a distinct species group, this group is to be diagnosed below.

Diagnosis. Fairly large, body length of the known species 7.5 to 9.6 mm (the last value for the specimens with abdomen extended)). Elytra moderately long, moderately and uniformly dilated posteriorly behind rounded but developed humeri; the known species with wings normally developed; posterior margin of the abdominal tergite 7 with evident white fringe. Abdomen, excluding the apical segments, nearly parallelsided.

Male. Posterior margin of the abdominal sternite 8 nearly straight, slightly sinuate at most, with neither conspicuous emarginations nor impressions; underside of the sternite punctured (and pubescent) somewhat denser medioposteriorly; no conspicuous spiculiferous and setaceous structures are developed; aedeagus with lateal sclerotized lobes of the phallobase extended to the side opposite to the basal opening; endophallus entirely membranous, without visible armature, excluding a small ring-shaped structure; operculum very small, rudimentary, extremely feebly sclerotized.

Female. Abdominal sternite 8 with broad rounded posterior margin.

Differ from other Lathrobium species by the combination of the characters of aedeagus (extended lateral lobes of the phallobase, entirely membranous endophallus, rudimentary operculum) and the mail terminalia without conspicuous emarginations and impressions.

Taxa included. Lathrobium (s. str.) ishiharai Hayashi, 1994 and L. (s. str.) ursinum Ryvkin, 2011 stat. nov.

Remarks. I can find no relations between the ishiharai group and other Lathrobii. The attempts ( Hayashi, 1994) to regard the nominate species as similar either with the heterogeneous pollens group or with L. dignum Sharp, 1874 systematic position of which requires a clarification seem to be inconsistent. Neither presence or absence of wings (especially for island territories) nor coloration of elytra may be used as sufficient characters in this case since these characters can be varying radically even within an only Lathrobium species. An analysis of relations with the monticola group (sensu Watanabe, 2000 et al.) would require a thorough revision of this group probably including its redefinition. Some resemblance to the sibiricum group in the structure of endophallus is not supported by other characters and is definitely a case of parallelism. Thus, we must hope that intermediate forms will be found to ascertain the phylogenetic relationships of the group.