Astenus grebennikovi Janák & Baňař, 2021

Janák, Jiří & Cz-, Petr Baňař, 2021, Two new species and new records of the genus Astenus from Madagascar (Coleoptera: Staphylinidae: Paederinae), Zootaxa 4980 (1), pp. 127-141 : 130-132

Astenus grebennikovi Janák & Baňař , sp. nov.

( Figs. 12–23 , 42–45 )

Type locality. Madagascar, Anjozorobe-Angavo

Type material. Holotype ♂: MADAGASCAR: “MADAGAS., Anjozorob. [ Anjozorobe ], -18.4118 47.9504, 1424m, 8.i.2019, sift [sifting], MD36, V. Grebennikov // HOLOTYPUS Astenus grebennikovi sp. nov., Janák & Baňař det. 2020” ( JJRC) . Paratypes: 1 ♂: “AJR/ Jan.2019 /sift5 C MADAGASCAR, ANJOZOROBE forest, 15.i.2019, sifting forest litter 1381m, S18°24’36.2” E47°56’42.3”, Winkler app. extr. P. Baňař lgt.” ( JJRC) ; 1 ♂: “AJR/ Jan.2019 /sift 8 C MADAGASCAR, ANJOZOROBE forest, 17.i.2019, sifting litter by big Pandanus 1394m , S18°24’35.5” E47°56’43.0”,Winkler app.extr. P.Baňař lgt.”( MMBC) ; 1♂:“AJR/ Jan.2019 /sift7C MADAGASCAR, ANJOZOROBE forest, 15.i.2019, sifting forest litter by big tree 1331m, S18°24’47.4” E47°56’33.1”, Winkler app. extr. P. Baňař lgt.” ( MMBC) ; 1 ♀: “AJR/ Jan.2019 /sift 4 C MADAGASCAR, ANJOZOROBE forest, 15.i.2019, sifting under Pandanus 1382m , S18°24’35.2” E47°56’42.5”, Winkler app. extr. P. Baňař lgt.” ( MMBC) . All paratypes with an additional label “ PARATYPUS Astenus grebennikovi sp. nov., Janák & Baňař det. 2020” .

Description: Body length 5.5–7.5 mm (M = 6.4 mm, HT = 5.5 mm), forebody length 3.0– 3.3 mm (M = 3.2 mm, HT = 3.0 mm). Dark brown, anterior part of head and sometimes also abdomen dark reddish brown, legs light yellow, antennomeres light reddish yellow with mostly slightly lighter first two antennomeres, mouthparts light reddish yellow ( Fig. 12 ).

Head ( Fig. 13 ) moderately convex, a quarter longer than wide (L/W = 1.26–1.31, M = 1.28, HT = 1.27). Surface with coarse and dense umbilicate punctures. Eyes moderately large, temples on average about 1.3 times as long as eyes (TL/EL 1.23–1.43, M = 1.33, HT = 1.43). Temples markedly narrowed posteriorly. Antennae long and slender, fifth antennomere about 3 times as long as wide (L/W = 3.00–3.32, M = 3.16, HT = 3.00), tenth antennomere about two and half as long as wide (L/W = 2.38–2.56, M = 2.44, HT = 2.56).

Pronotum ( Fig. 13 ) egg-shaped, moderately convex, with shallow lateral impressions, about a quarter longer than wide (L/W = 1.23–1.30, M = 1.28, HT = 1.28) and moderately narrower than head (PW/HW = 0.86–0.90, M = 0.87, HT = 0.87). Sides markedly narrowed posteriorly, slightly emarginated in posterior half. Surface with coarse and dense umbilicate punctures similar as on head, unpunctured midline missing.

Elytra ( Fig. 13, 14 ) elongate with rounded sides, concave along suture, about 1.4 times longer than wide (R = 1.34–1.49, M = 1.41, HT = 1.49). Surface moderately coarsely and densely punctured. Interstices shining, without microscupture. Shoulders with 4 tubercules bearing long, protruding fragile spines ( Fig. 14 ) [in most specimens including HT most spines broken and missing]. Sides with additional a few shorter and less protruding spines.

Abdomen ( Fig. 12 ) slightly widened to segment VI, finely and densely punctured. Interstices shining, without microsculpture.

Male. Posterior margin of sternite VII broadly emarginate and with almost 25 moderately long spines ( Fig. 22 ), sternite VIII long and narrow, with triangular emargination in posterior fifth ( Fig. 23 ). Aedeagus ( Figs. 15–21 ) long and slender, about 1 mm long (AL = 0.97–1.02 mm, M = 0.99 mm, HT = 0.99 mm). Median lobe in ventral view narrow, sides markedly emarginate in middle part and with relatively wide sub-rounded point. Median lobe in lateral view regularly bent. Female. Sternite VIII largely rounded posteriorly.

Differential diagnosis. The new species is to be arranged in the last key of Madagascan Astenus species ( Janák & Lecoq 2007) in the couplet 10 near A. duflosi Lecoq, 1996 , but it differs externally by more rounded temples and in males by markedly emarginate posterior margin of sternite VII and different shape of the aedeagus (compare Figs. 31–39 for details).

Etymology. This species is dedicated to Vasily Grebennikov, specialist in various groups of Coleoptera , who collected the holotype of the new species.

Distribution. Astenus grebennikovi Janák & Baňař sp. nov. is currently recorded only from the Anjozorobe-Angavo [Paysage Harmonieux Protègé du Complexe Anjozorobe-Angavo] in the northern central part of Madagascar.

Bionomics. The type series was sifted from forest litter ( Figs. 42–45 ). One teneral specimen was collected in January.

Figures

FIGURES 12–23. Astenus grebennikovi Janák & Baňař sp. nov. 12, 13, 15, 16, 19–23, holotype; 14, 17, 18, paratypes; 12, habitus; 13, forebody; 14, elytra; 15, 17, 19, aedeagus, lateral view; 16, 18, 20, 21, aedeagus, dorsal view; 22, posterior part of male sternite VII; 23, male sternite VIII; 15, 16, 19–21, transmitted light; 17, 18, reflected light. Scale bar: 1.0 mm (Fig. 12); 0.5 mm (Figs.13, 16–18); 0.1 mm (Figs. 19–21).

FIGURES 42–43. Forest of Anjozorobe-Angavo. 42, View from camping site; 43, forest detail (both photos by M. Trýzna).

FIGURES 44–45. Forest of Anjozorobe-Angavo, microhabitats of Astenus grebennikovi Janák & Baňař sp. nov. 42, detail of forest undergrowth; 43, detail of microhabitat of sift sample nr. 4 under Pandanus plant.

FIGURES 31–39. Astenus duflosi Lecoq. 31, 32, 36–39, Vohimana; 33–35, Andasibé; 31, habitus; 32, forebody; 33, 35, aedeagus, lateral view; 34, aedeagus, ventral view; 36, 37, apical part of aedeagus, ventral view; 38, posterior part of male sternite VII; 39, male sternite VIII; 33–35, reflected light; 36, 37, transmitted light. Scale bar: 1.0 mm (Fig. 31), 0.5 mm (Figs. 33–35, 38–39), 0.1 mm (Figs. 36 –37).