Bryaxis samothracicus, Assing, 2019

Assing, Volker, 2019, On the Staphylinidae of the Greek island Samothraki (Insecta Coleoptera), Linzer biologische Beiträge 51 (2), pp. 881-906 : 902-903

Bryaxis samothracicus BRACHAT nov.sp. ( Figs 29-30 , 35 )

T y p e m a t e r i a l: Holotype ♂: "GR – Samothraki [18b], Therma, 40°30'01''N, 25°36'23''E, 20 m, mixed forest, sifted, 15.IV.2019, V. Assing / Bryaxis samothracicus spec.nov. ♂, det. Brachat / Holotypus " (cBra) . Paratypes (all in cBra): 1♂: same data as holotype ; 1♂, 1♀: "GR – Samothraki [21a], Therma, 40°29'49''N, 25°36'31''E, 30 m, bank of stream, litter sifted, 15.IV.2019, V. Assing" ; 2♀♀: "GR – Samothraki [22], WSW Ano Meria, 40°27'39''N, 25°38'26''E, 890 m, roots and litter, 11.IV.2019, V. Assing" ; 3♀♀: "GR – Samothraki [23], WSW Ano Meria, 40°27'39''N, 25°38'32''E, 900 m, roots and litter, 11.IV.2019, V. Assing" .

E t y m o l o g y: Named after the island where this species is probably endemic.

D e s c r i p t i o n: Body length 1.55-1.70 mm. Body reddish-brown, glossy, and with suberect yellow pubescence (length of setae 0.1 mm), with scattered longer setae.

Head weakly transverse (length 0.30-0.31 mm; width 0.32-0.35 mm). Eye size highly variable, in male with 10-20 and in female with 9-12 ommatidia. Frontal lobe 0.18 mm broad. Antenna 0.64-0.68 mm long; antennomeres III 1.25 x times as long as broad, IV- VII globular and as broad as III, VIII shorter, IX transverse and slightly broader and longer than VIII, X more distinctly transverse, longer and broader than IX, and XI large, slightly longer than the combined length of VIII-X and about three times as long as broad. Maxillary palpomeres II and III with more or less numerous tubercles, IV petiolate (length 0.24-0.27 mm; width 0.09-0.10 mm). Pronotum distinctly longer and broader than head, weakly transverse (length 0.36-0.39 mm; width 0.38-0.41 mm). Elytra weakly transverse (length 0.58-0.61 mm; width 0.66-0.68 mm), with marked humeral angles and with sparse, but distinct punctation. Hind wings present. Legs slender.

♂: head ventrally with transverse gular impression with distinctly elevated anterior margin; antennomere I ( Fig. 29 ) oblong (length 0.15 mm; width 0.11 mm) and distally broadened, on inner side with tubercle at apical fifth; antennomere II ( Fig. 29 ) narrower, as long as broad (0.06 mm), on inner side with fine longitudinal carina; profemur dilated, basally with a distinct impression ventrally; protibia with a tooth and a deep incision at apical third; mesofemur weakly, metafemur strongly dilated; metatibia broadened, with a spine and a deep incision at apical third and with a small apical spine; metaventrite impressed in posterior half and with median sulcus; aedeagus ( Fig. 30 ) 0.40-0.42 mm long and with internal structures of distinctive shapes; parameres narrowed in apical third and with three subapical setae.

♀: antennomere I twice as long as broad (lengh 0.12 mm; width 0.06 mm); antennomere II weakly oblong (length 0.06 mm; width 0.05 mm); metaventrite flattened in posterior half and with median sulcus.

C o m p a r a t i v e n o t e s: The new species is distinguished from the highly similar B. simoni (REITTER, 1880), a widespread species in the southern Balkans, by the

shapes of the aedeagus and of the male antennomeres I and II. The aedeagus of B. simoni is illustrated in KARAMAN (1957).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Bryaxis samothracicus is most likely endemic to Samothraki. The specimens were sifted from Platanus and oak litter near a stream and at the margin of a pasture, as well as from litter and grass roots on rocky slopes with scattered oak trees at altitudes of 20- 900 m. One of the localities is illustrated in Fig. 35 .

Figures

Figs 27-32: Apimela procera (27), Tychobythinus assingi (28), Bryaxis samothracicus (29-30), and Bryaxis pangeonicus (31-32): (27) female sternite VIII; (28, 30, 32) aedeagus in dorsal view; (29, 31) male antennomeres I-II. Scale bars: 27: 0.2 mm; 28, 30, 32: 0.1 mm; 29, 31: without scale.

Fig. 35: Type locality of Cephennium samothracicum and Scydmoraphes samothracicus (sample number 16). Bryaxis samothracicus, too, was found in this locality.