Atheta ( Anopleta ) digitalis ASSING, 2019

Atheta ( Anopleta) digitalis ASSING View in CoL spec. nov.

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( Figs 12–19 View Figs 1–19 )

Type material: Holotype ♂: “ N35°19'10 E23°54'46, GR Westkreta (16), Omalos 1110 m 16.3.2018, l. Brachat & Meybohm / Holotypus ♂ Atheta digitalis sp. n. det. V. Assing 2018” (cAss) GoogleMaps . Paratypes: 1 ♀: same data as holotype (cAss); 1 ♂: “GR – Crete [17a], NW Dikti Oros, Limnakaro , 35°08'08"N, 25°29'00"E, 1170 m, sifted, 30.III.2012, V. Assing ” (cAss) GoogleMaps .

Etymology: The specific epithet (Latin, adjective: of a finger) alludes to the shape of one of the internal structures of the aedeagus.

Description: Body length 2.2–2.3 mm; length of forebody 0.9–1.1 mm. Habitus as in Fig. 12 View Figs 1–19 . Coloration: body black; legs dark-brown to blackish-brown with the bases and apices of the tibiae and all of the tarsi pale yellowish; antennae black.

Head ( Fig. 13 View Figs 1–19 ) weakly transverse, with or without very shallow impression in the middle; punctation moderately dense and extremely fine, barely visible even at a magnification of 100 x; interstices with pronounced microreticulation. Eyes large, as long as, or slightly longer than postocular portion in dorsal view. Antenna ( Fig. 14 View Figs 1–19 ) approximately 0.6 mm long; antennomere IV weakly transverse; antennomeres V–X of gradually increasing width and increasingly transverse, X approximately 1.5 times as broad as long.

Pronotum ( Fig. 13 View Figs 1–19 ) small, approximately 1.2 times as broad as long and 1.1 times as broad as head; punctation and microsculpture similar to those of head; pubescence white, directed transversely laterad in lateral portion and apparently (difficult to assess in type specimens) anteriad in anterior third and posteriad in posterior two-thirds of midline.

Elytra ( Fig. 13 View Figs 1–19 ) approximately 1.2 times as long as pronotum; punctation and microsculpture similar to those of head and pronotum.

Abdomen ( Fig. 15 View Figs 1–19 ) narrower than elytra, broadest at segment VI; punctation fine, denser on anterior than on posterior tergites; all tergites with pronounced isodiametric microsculpture, but glossy; posterior margin of tergite VII with palisade fringe; tergite VIII subject to sexual dimorphism.

♂: posterior margin of tergite VIII ( Fig. 16 View Figs 1–19 ) truncate to weakly concave and crenulate; sternite VIII with moderately convex posterior margin; median lobe of aedeagus ( Figs 17–18 View Figs 1–19 ) small, 0.23 mm long; crista apicalis pronounced; internal structures of distinctive shape, the less sclerotized one shaped like a finger in lateral view.

♀: posterior margin of tergite VIII of similar shape as in male, but posterior margin not crenulate; posterior margin of sternite VIII less convex than in male; spermatheca ( Fig. 19 View Figs 1–19 ) small and of highly distinctive shape, distal portion strongly dilated.

Comparative notes: Based on the similar sexual characters, A. digitalis appears to be closely allied to A. puberula (SHARP, 1869) . It is distinguished from this species by significantly smaller size ( A. puberula : body length 2.5–2.8 mm), shorter antennae, the coloration of the legs (yellow in A. puberula ), and by the primary and secondary sexual characters. In A. puberula , the posterior margin of the male tergite VIII is more concave and has a distinct lateral tooth on either side, the posterior margin of the male sternite VIII is strongly convex, the median lobe of the aedeagus is much larger ( A. puberula : median lobe approximately 0.35 mm long) and has differently shaped internal structures, the posterior margin of the female sternite VIII has a pronounced median concavity, and the spermatheca is much larger and of different shape.

Distribution and natural history: This species is currently known from two localities, one in West Crete and one in the east of the island. The specimen from East Crete was recorded as Atheta ( Microdota) sp. by ASSING (2013). The specimens were sifted from litter at an altitude of 1110 m (specimens from the type locality) and from grass, litter, and moss near snowfields at an altitude of 1170 m (male from Dikti).