Astenus ambohitantelyensis 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 : 128-130

Astenus ambohitantelyensis Janák & Baňař , sp. nov.

( Figs. 1–11 , 40–41 )

Type locality. Madagascar, Ambohitantely Special Reserve

Type material. Holotype ♂: “ABT/ Sept.2011 /24 MADAGASCAR, AMBOHITANTELY Spec. Res.; 5.ix.2011; S18°11’43.3‘‘ E47°17’22.5‘‘, 1640m; sifting of forest litter under palm tree, Winkler app. Extraction, L.S. Rahanitriniaina lgt. // HOLOTYPUS Astenus ambohitantelyensis sp. nov., Janák & Baňař det. 2020” ( MMBC) . Paratypes: 1 ♀: first label same as the holotype ( MMBC) ; 1 ♂: “ABT/ Sept.2011 /14 MADAGASCAR, AMBOHITANTELY Spec. Res. ; 3.ix.2011; S18°10’57.6‘‘ E47°17’19.7‘‘, 1544m; sifting forest litter and dry fern, Winkler app. extr.; L.S. Rahanitriniaina lgt.” ( JJRC) ; 1 ♂: “ABT/06/2011 MADAGASCAR 2011, Ambohitantely Spec. Res. ; 19.iv., S18°11’02.5‘‘, E47°17’12.9‘‘; 1577m, sifting forest litter, Winkler apparatus extraction; L.S. Rahanitriniaina lgt.” ( MMBC, aedeagus missing) , 1 ♀: “ABT/ Sept.2011 /21 MADAGASCAR, Ambohitantely Spec. Res. ; 5.ix.2011; S18°11’23.1‘‘ E47°17’38.1‘‘, 1635m; sifting of forest litter and dry fern; secodary forest; Winkler app. extraction; L.S. Rahanitriniaina lgt.” ( MMBC) . All paratypes with an additional label “ PARATYPUS Astenus ambohitantelyensis sp. nov., Janák & Baňař det. 2020” .

Description: Body length 4.7–6.4 mm (M = 5.4 mm, HT = 4.7 mm), forebody length 2.4–2.6 mm (M = 2.6 mm, HT = 2.4 mm). Black to dark brown, anterior part of head and abdomen dark brown, femora and tibiae brown, knees and tarsi light reddish yellow, antennomeres 1–7 dark reddish brown, antennomeres 8–11 and mouthparts light reddish yellow ( Fig. 1 ).

Head ( Fig. 2 ) moderately convex, a fifth longer than wide (L/W = 1.17–1.22, M = 1.20, HT = 1.20). Surface with coarse and dense umbilicate punctures. Eyes moderately large, temples on average about 1.2 times as long as eyes (TL/EL 1.16–1.30, M = 1.20, HT = 1.18). Temples moderately narrowed posteriorly. Antennae moderately short, fifth antennomere about 2.5 times longer than wide (L/W = 2.50–2.73, M = 2.63, HT = 2.50), tenth antennomere about twice as long as wide (L/W = 1.93–2.11, M = 2.02, HT = 2.08).

Pronotum ( Fig. 2 ) egg-shaped, moderately convex, a quarter longer than wide (L/W = 1.19–1.26, M = 1.24, HT = 1.25) and moderately narrower than head (PW/HW = 0.87–0.89, M = 0.88, HT = 0.87). Sides markedly narrowed posteriorly. Surface, except for very narrow unpunctured midline with coarse and dense umbilicate punctures similar as on head.

Elytra ( Figs. 2, 3 ) elongate with rounded sides, concave along suture, about 1.3 times longer than wide (R = 1.26–1.34, M = 1.30, HT = 1.30). Surface moderately coarsely and densely punctured. Interstices shining, without microscupture. Shoulders with 2 tubercules bearing long, protruding fragile spines ( Fig. 3 ) [in most specimens including HT broken and missing]. Sides with additional a few shorter and less protruding spines.

Abdomen ( Fig. 1 ) slightly widened to segment VI, finely and densely punctured. Interstices shining, without microsculpture.

Male. Posterior margin of sternite VII very slightly, almost invisible emarginate and with almost 40 rod shaped moderately long spines ( Fig. 10 ), sternite VIII long and narrow, with triangular emargination in posterior quarter ( Fig. 11 ). Aedeagus ( Figs. 4–9 ) 0.77 mm long. Median lobe in ventral view moderately wide, sides slightly emarginate in middle part and with small narrow sub-rounded point. Median lobe in lateral view with distinct subapical dent.

Female. Sternite VIII largely rounded posteriorly.

Differential diagnosis. The new species is to be arranged in the last key of Madagascan Astenus ( Janák & Lecoq 2007) in the couplet 12b near A. ambondrombe Janák & Lecoq, 2007 and A. ambrensis Janák, 2008 and differs from these species by very slightly, almost invisible emarginated posterior margin of the male sternite VII with moderately long rod shaped spines and different shape of aedeagus (see Figs. 38–44 in Janák & Lecoq, 2007 and Figs. 2–6 in Janák, 2008). There are also some external differences among these species – the color of A. ambohitantelyensis Janák & Baňař sp. nov. is much darker and the pronotum and elytra are on average longer than in remaining two species, but these characters are quite variable (see Fig. 39 in Janák & Lecoq (2007) and Fig. 1 in Janák (2008) and measurements in the descriptions for details).

Etymology. This species is named the after the type locality – Ambohitantely Special Reserve.

Distribution. Astenus ambohitantelyensis Janák & Baňař sp. nov. is currently recorded only from the Ambohitantely Special Reserve in the northern central part of Madagascar

Bionomics. All specimens were collected in siftings of forest litter, palm trees and dry ferns in an indigenous or secondary forests at an altitude of 1540–1640 m a.s.l. ( Figs. 40, 41 ).

Figures

FIGURES 1–11. Astenus ambohitantelyensis Janák & Baňař sp. nov. 1, 2, 4, 5, 8–11, holotype; 3, 6, 7, paratypes; 1, habitus; 2, forebody; 3, elytra; 4, 6, 8, aedeagus, lateral view; 5, 7, 9, aedeagus, ventral view; 10, posterior part of male sternite VII; 11, male sternite VIII; 4, 5, 8, 9, transmitted light; 6, 7, reflected light. Scale bar: 1.0 mm (Fig. 1); 0.5 mm (Figs. 2–7, 10–11), 0.1 mm (Figs. 8–9).

FIGURES 40–41. Forest of Ambohitantely Special Reserve. 41, View from administrative buildings close to main entrance; 42, detail of forest undergrowth.

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).

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.