Hydrosmecta insularum ASSING, 2019

Assing, Volker, Brachat, Volker & Meybohm, Heinrich, 2019, Monograph of the Staphylinidae of Crete (Greece). Part II. Descriptions of new species (Insecta: Coleoptera), Beiträge Zur Entomologie = Contributions to Entomology 69 (2), pp. 239-289 : 244

Hydrosmecta insularum ASSING spec. nov.

urn:lsid:zoobank.org:act:A5DC3A8F-AC05-46F0-B3D0-A97CF126AB8F

( Figs 20–31 )

Type material: Holotype ♂: “GR – Crete [59], WSW Ag. Nikolaos , Katharo plateau , 1100 m, stream, 35°08'19"N, 25°33'36"E, 27.III.2018, V. Assing / Holotypus ♂ Hydrosmecta insularum sp. n. det. V. Assing 2018” (cAss) . Paratypes: 39 ♂♂, 37 ♀♀: same data as holotype (cAss, MNB); 3♂♂, 9♀♀: “GR – Crete [60], WSW Ag. Ni kolaos, Katharo plateau, 1090 m, stream, 35°08'48"N, 25°33'33"E, 27.III.2018, V. Assing ” (cAss, MNB); 41 ♂♂, 44 ♀♀: “GR – Crete [61], WSW Ag. Nikolaos, Katharo plateau, 1110 m, stream, 35°08'14"N, 25°34'15"E, 28.III.2018, V. Assing ” (cAss, cFel); 16 ♂♂, 16 ♀♀: “GR – Crete [12], WSW Ag. Nikolaos, Katharo plateau, 1110 m, stream, 35°08'14"N, 25°34'15"E, 10.IV.2014, V. Assing ” (cAss, MNB); 8♀♀: “ GREECE:Ikaría [18], NE Pe zi, 37°33'51"N, 26°04'46"E, 860 m, stream bank, floated, 12.IV.2017, V. Assing ” (cAss, MNB); 2 ♂♂: “ GREECE: Lesbos [27a] 16 km ENE Kalloni, 39°15'02"N, 26°23'14"E, 120 m, 24.III.2016, V. Assing & A. Hetzel ” (cAss); 1 ♂: “GR – Samothraki [16a], W Lakkoma, 40°25'57"N, 25°30'54"E, 20 m, gravel river bank, 16.IV.2019, V. Assing ” (cAss); 7 ♂♂, 10 ♀♀: “GR – Samothraki [33], SE Ano Meria, 40°26'52"N, 25°41'46"E, 5 m, stream gravel, 14.IV.2019, V. Assing ” (cAss, MNB); 6 ♀♀: “GR – Samothraki [34b], ESE Ano Meria, 40°27'41"N, 25°41'25"E, 30 m, stream gravel, 17.IV.2019, V. Assing ” (cAss, MNB); 1 ♀: “GR – Samothraki [38a], SE Kamariotissa, 40°26'48"N, 25°29'53"E 40 m, stream gravel, 16.IV.2019, V. Assing ” (cAss) .

Etymology: The specific epithet is the genitive plural of the Latin noun insula (island) and reflects the fact that this species is currently known only from islands.

Description: Body length 2.2–2.9 mm; length of forebody 1.1–1.3 mm. Habitus as in Fig. 20 . Coloration: body black with the elytra slightly paler; legs yellowish to darkyellowish; antennae blackish-brown to black.

Head ( Fig. 21 ) approximately as broad as long or weakly transverse; punctation dense and fine, barely visible in the pronounced microreticulation. Eyes large, much longer than postocular portion in dorsal view. Antenna ( Fig. 22 ) approximately 0.9 mm long; antennomeres III shorter than II, IV distinctly oblong, approximately 1.5 times as long as broad, V–X distinctly oblong, but less than twice as long as broad, and XI approximately three times as long as broad.

Pronotum ( Fig. 21 ) 1.15–1.20 times as broad as long and 1.10–1.15 times as broad as head, broadest anterior to middle; disc weakly convex in cross-section, in the middle depressed or shallowly impressed; pubescence directed anteriad along midline and transversely laterad in lateral portions; punctation dense and extremely fine, finer than that of head; disc with pronounced microreticulation.

Elytra ( Fig. 21 ) approximately as long as pronotum; punctation very dense and fine; interstices with microsculpture. Hind wings fully developed.

Abdomen narrower than elytra; anterior impressions of tergites III–V shallow; punctation fine and moderately dense, denser on anterior than on posterior tergites; interstices with distinct microreticulation; posterior margin of tergite VII with palisade fringe; tergite and sternite VIII with pronounced sexual dimorphism.

♂: tergite VIII ( Fig. 23 ) distinctly transverse, posterior margin more or less truncate; sternite VIII ( Fig. 24 ) much longer than tergite VIII, its posterior margin weakly concave, nearly truncate; median lobe of aedeagus ( Figs 25–27 ) 0.32–0.36 mm long and of highly distinctive shape; paramere ( Fig. 28 ) slightly longer than median lobe and not distinctly modified.

♀: tergite VIII ( Fig. 29 ) less transverse than in male, but with posterior margin of similar shape; sternite VIII ( Fig. 30 ) slightly longer than tergite VIII, its posterior margin convex and in the middle distinctly concave; spermatheca distinctive ( Fig. 31 ).

Comparative notes: Based on the modifications of the abdominal segment VIII and on the derived morphology of the median lobe of the aedeagus, H. insularum belongs to Hydrosmecta sensu strictu. It is distinguished from other species of this group especially by the conspicuous shape of the median lobe of the aedeagus. In addition, it is characterized by the male secondary sexual characters (shape of sternite VIII) and by the shape of the spermatheca.

Distribution and natural history: The currently known distribution is confined to the Greek islands Crete, Ikaría, Lesbos, and Samothraki. The species was reported from Lesbos as Hydrosmecta sp. 2 in ASSING (2016) and from Ikaría as Hydrosmecta sp. in ASSING (2017). The specimens were washed from fine gravel along small streams at altitudes of 110–1110 m.

Figures

Figs 20–38: Hydrosmecta insularum (20–31) and Geostiba inexsecta (32–38): habitus (20); forebody (21); antenna (22); male tergite VIII (23, 32); male sternite VIII (24, 33); median lobe of aedeagus in lateral and in ventral view (25–27, 34–35); paramere (28); female tergite VIII (29, 36); female sternite VIII (30, 37); spermatheca (31, 38). Scale bars: 20: 1.0 mm; 21: 0.5 mm; 22–24, 29–30, 32–33, 36–37: 0.2 mm; 25–28, 31, 34–35, 38: 0.1 mm.