Astenus (Eurysunius) corumensis, Anlaş, 2024

Anlaş, Sinan, 2024, On the subgenus Eurysunius Reitter of Turkey IX. Three new species from central northern Anatolia, with an identification key to Turkish species (Coleoptera: Staphylinidae: Paederinae, Astenus), Zootaxa 5474 (1), pp. 68-76 : 69-70

Astenus (Eurysunius) corumensis sp. n. ( Figs. 1–8 ; Map 1 )

Type material. Holotype: TURKEY: ♂, ‘‘ Çorum, Kargı, Bozarmut 3 km N, 41°14'12''N, 34°28'59''E, 1400 m, 03.V.2021, leg. Örgel, Kacar & Çelik. / Holotypus ♂, Astenus (Eurysunius) corumensis sp. n. det. S. Anlaş 2024” <red printed label> ( AZMM) . Paratypes: 4♂♂, 5♀♀, same data as holotype <all paratypes with red printed label> ( AZMM) .

Description. Habitus as in Fig. 1 . Body 4.4–4.8 mm long. Coloration: head and pronotum blackish, posterior half of elytra reddish, with anterior area blackish; abdomen dark brown or blackish, antennae and legs reddish.

Head transverse, approximately 1.2 times as wide as long ( Figs 1–2 ); dorsal surface distinctly convex; punctation shallow, dense, and umbilicate; pubescence yellowish, very sparse and short. Eyes relatively small in size with very slightly protruding, in dorsal view distinctly shorter than postocular region. Antennae moderately slender, 1.18–1.23 mm long, all antennomeres oblong, antennomere III approximately 2.1 times as long as wide ( Fig. 1 ).

Pronotum slightly transverse, 1.15 times as wide as long ( Figs 1–2 ); narrower than head, approximately 0.85– 0.90 times as broad as head; posterior margin slightly convex; laterally with a shallow impression on either side; punctation somewhat coarser, and umbilicate; pubescence of similar as that of head. Anterior and posterior margin of pronotum with 2–4 black setae; lateral margins each with two long black setae (on average 2.2–2.3 mm); one in anterior angle and one in posterior angle.

Elytra distinctly transverse, 1.70–1.75 times as long, 1.25 times as wide as pronotum ( Figs 1–2 ); approximately 0.70 times as long as pronotum; microsculpture absent; punctation granulose; pubescence of similar as that of pronotum but slightly denser than those of head and pronotum; posterior margin of each elytron with variable number of long black setae. Hind wings completely reduced.

Abdomen 0.80–0.85 times as broad as elytra; widest at segment V, segments III–VI distinctly transverse ( Fig. 1 ), punctation dense and very fine on anterior tergites, gradually decreasing in density from tergite III to tergite VIII, moderately dense on tergites VII and VIII; interstices with distinct fine microsculpture; pubescence yellowish and decumbent; posterior margin of tergite VII with palisade fringe.

♂: sternite VII in posterior median area slightly depressed and with modified dark and short setae, posterior margin very slightly concave ( Fig. 3 ); posterior incision of sternite VIII in middle narrow and acute, pubescence unmodified ( Fig. 4 ); aedeagus 0.68–0.73 mm long and as in Figures 5–8 , apical portion of ventral process with stout-shaped in lateral view.

Comparative notes. This new species is distinguished from all its congeners by the different morphology of the aedeagus. From other species occurring in central northern Anatolia, it is additionally separated as follows:

From A. bicoloratus Assing, 2002 (Ordu) by the presence of two (vs. one) long setae on the lateral margins of the pronotum, by the different coloration of the forebody ( A. bicoloratus : Head and pronotum dark brown, anterior 2/3 of elytra blackish, posterior 1/3 of elytra yellow), by the less transverse head ( A. bicoloratus : Head 1.3 times as wide as long).

From A. paphlagonicus Assing, 2002 (Kastamonu and Bolu) by the different coloration ( A. paphlagonicus : elytra yellowish, at most very narrowly infuscate anteriorly; legs and antennae yellowish red), and by the different shape of the aedeagus both ventral and lateral view, especially apically more stouter in lateral view.

From Astenus kirani Anlaş, 2021 (Sivas) on average by the slightly larger body ( A. kirani : 3.9–4.5 mm), by the slightly narrower pronotum and abdomen, by the presence umbilicate punctation on pronotum (vs. non-umbilicate), by the broader posterior incision in sternite VIII, and by the different shape of the aedeagus both ventral and lateral view, apically more stouter in lateral view and more broader in ventral view.

From Astenus sivasicus Anlaş, 2019 (Sivas), by the longer antennae ( A. sivasicus : antennae 1.0– 1.1 mm), by the slightly narrower pronotum, by the slightly broader posterior incision in sternite VIII, and by the different shape of the aedeagus both ventral and lateral view, especially apically more broader in ventral view.

For descriptions and illustrations of these species see Assing (2002), Anlaş (2019, 2021) and also see key to the Turkish Eurysunius species.

Etymology. The name is derived from the Çorum province, where the type locality is situated.

Distribution and bionomics. The species was collected from only one locality from Bozarmut village environs in Kargı district, Çorum province ( Map 1 ), in a grassland area at an altitudes of 1400 m. The type specimens were collected in the nests of an unidentified Tetramorium species.

Figures

MAP 1. Distribution of Astenus (Eurysunius) species in Turkey (28 species)

FIGURES 1–8. Astenus (Eurysunius) corumensis sp. n. 1—habitus; 2—forebody; 3—Male sternite VII; 4—Male sternite VIII; 5, 6—Aedeagus in lateral view; 7, 8—Aedeagus in ventral view. Scale bars: 0.5 mm (Figs. 1–2), 0.2 mm (Fig. 3–8).