Lobrathium ancoriferum, Assing, 2017

Assing, Volker, 2017, A revision of Palaearctic Lobrathium. VI. Two new species from Armenia and Taiwan, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 299-306 : 301-303

Lobrathium ancoriferum nov.sp. ( Figs 1-7 )

T y p e m a t e r i a l: Holotype 3: " Erevan, Asni, ASSR. 13.5.55 / Holotypus 3 Lobrathium ancoriferum sp. n., det. V. Assing 2017" (cKal).

E t y m o l o g y: The specific epithet (Latin, adjective: carrying an anchor) alludes to the shape of the basal internal structure of the aedeagus in lateral and in dorsal view.

D e s c r i p t i o n: Body length 8.0 mm; length of forebody 4.1 mm. Coloration: head and pronotum reddish; elytra pale-reddish; abdomen with segments III-VI blackish-

brown, VII brown, and VIII-X reddish; legs pale-reddish; antennae dark-reddish.

Head ( Fig. 1 ) 1.06 times as long as broad; dorsal surface weakly convex in cross section; lateral margins behind eyes weakly converging in dorsal view; posterior angles weakly marked; punctation dense and moderately coarse, sparser in median and in anteromedian dorsal portion. Eyes approximately half as long as distance from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 2 ) 2.7 mm long.

Pronotum ( Fig. 1 ) 1.24 times as long as broad and 0.94 times as broad as head; punctation similar to that of head, but less dense than that in lateral and posterior portions of head; impunctate median band narrow.

Elytra ( Fig. 1 ) 0.92 times as long as pronotum and 1.1 times as broad as head; humeral angles moderately marked; punctation coarse and partly arranged in irregular rows; interstices without microsculpture.

Abdomen as broad as elytra; punctation moderately dense and moderately fine; anterior impressions of tergites III-VII with pronounced microreticulation, remainder of tergal surfaces with fine transverse microsculpture; posterior margin of tergite VII with palisade fringe.

3: posterior margin of tergite VIII convex; sternite VII strongly transverse and with extensive postero-median impression, pubescence unmodified; sternite VIII ( Fig. 3 ) weakly transverse, along middle with extensive impression, this impression with two oblong clusters of numerous modified, short and stout black setae, posterior excision large and approximately one-fifth as deep as length of sternite; aedeagus ( Figs 4-5 ) 1.5 mm long; ventral process large, blade-shaped, and apically acute, ventrally with two transverse carinae in apical half and numerous granules in basal half; internal sac with a large anchor-shaped basal structure, with an apical pair of two strongly curved spines and with an apical pair of long series of small spines ( Figs 6-7 ).

♀: unknown.

C o m p a r a t i v e n o t e s: Lobrathium ancoriferum is distinguished from all its congeners by the male primary and secondary sexual characters. Regarding the shape of the ventral process of the aedeagus, L. ancoriferum somewhat resembles L. schillhammeri and L. rugipenne , from which the new species differs as follows:

from L. schillhammeri by completely different coloration ( L. schillhammeri : body black, except for two yellowish spots in the posterior portion of the elytra), larger size, a more oblong head, shorter elytra with less pronounced humeral angles, the different shape and chaetotaxy of the male sternite VIII, and a much larger aedeagus ( L. schillhammeri : aedeagus barely 1 mm long) of different shape;

from the similarly large L. rugipenne by different coloration ( L. rugipenne : head and pronotum black, elytra bicoloured), a less convex head in cross-section, shorter and more slender elytra with less pronounced humeral angles, and by the shape and chaetotaxy of the male sternite VIII ( L. rugipenne : posterior margin of sternite VIII with a conspicuous fringe of dense dark setae).

From the widespread L. multipunctum , which is sometimes of similarly pale coloration and which may have similarly short elytra, L. ancoriferum is readily distinguished by slightly larger size, a less convex head (cross-section), much less coarse and less regularly seriate punctation of the elytra, less fine and less dense punctation of the abdomen, by the shape and chaetotaxy of the male sternite VIII, and by the completely different shape of the aedeagus.

D i s t r i b u t i o n: The type locality is situated near Yerevan, Armenia. Additional data are not available.

Figures

Figs 1-7: Lobrathium ancoriferum nov.sp.: (1) forebody; (2) antenna; (3) male sternite VIII; (4-5) aedeagus in lateral and in ventral view; (6-7) apical internal structures in lateral and dorsal view. Scale bars: 1-2: 1.0 mm; 3-5: 0.5 mm; 6-7: 0.1 mm.