Acylophorus tristis Jarrige, 1965

Janák, Jiří, 2018, Revision of the genus Acylophorus Nordmann, 1837 from Madagascar and Mascarene Islands (Coleoptera: Staphylinidae: Staphylininae: Acylophorina), Zootaxa 4462 (2), pp. 151-191 : 153-157

Acylophorus tristis Jarrige, 1965

( Figs. 1–21, 166, 167, 172)

Acylophorus tristis Jarrige, 1965: 140 ; Herman, 2001: 3038.

Type locality. Madagascar, Tananarive [Antananarivo], ca. 18 54' S, 47 31' E.

Type material examined. Holotype ♂: MADAGASCAR: “Tananarive, Mdg., Dr Ch. Nodier”, “ TYPE ”, “ A. tristis Jarrige ” ( MHNP).

Additional material examined. MADAGASCAR: 2 ♂, 1 ♀: C Madagascar, Antananarivo: Fenomanana , 1250–1350 m , 20.3.2001, swamp, treading, J. Janák ( JJRC); 1 ♀: C Madagascar, Antananarivo: Fenomanana , 1250–1350 m , 26.1.2004, swamp, treading, 18° 55' S, 47° 32' E, J. Janák ( JJRC); 1 ♀: C Madagascar, Antananarivo , 1.IV.06, sifted litter, G. de Rougemont lgt. ( GROG); 2 ♀: Madagascar Est, Andasibé ( Périnet ), 900– 1000 m, 6. – 7.2.1993, J. Janák lgt. ( JJRC); 1 ♀: E Madagascar, 32 km ESE of Betroka, Vohitrosa forest , 0.5 km S of ▲ 1798 m, 1650–1700 m, 25. – 28.12.1998, meadow, lighted swamp, treading, J. Janák ( JJRC); 1 ♀: 30 km SE of Betroka, 3 km NE of Tsanerena , 900 m , 15.12.1998, Ivahona, river alluvions, J. Janák lgt. ( JJRC); 3 ♂, 1 ♀: Sendrisoa , S of Ambalavao, Manambolo riv., 1200 m , 19.4.2001, treading on river bank, J. Janák ( JJRC); 13 ♂, 10 ♀: SE Madagascar: 21 km NE of Esira, Col de Marotaolana , 1100–1200 m, 1. – 2.2.2004, 24° 14' S, 46° 53' E, swamp, treading, J. Janák lgt. ( JJRC); 1 ♂: Madagascar Ouest, Manindray, E of Sakahara , 700–800 m , 30.1.1995, bord d’un ruisseau [brook bank], Pandanus, bambous, J. Janák lgt. (JJRC).

Redescription (n=10). Body length 6.9–8.7 mm (M= 7.9 mm, HT= 7.8 mm), forebody length 3.2–4.0 mm (M= 3.7 mm, HT= 3.7 mm) ( Fig. 1). Body black, abdominal tergites at most slightly iridescent; antennae brownish black with base of first two segments and segments 3–4 reddish; legs reddish brown, tarsi and maxillary palpi reddish.

Head rounded triangular ( Fig. 2), about as long as wide (L/W=0.98–1.02, M=1.00, HT=0.98), markedly widened behind eyes, with two pairs of interocular setae. Temples markedly shorter than eyes (R=0.45–0.54, M=0.49, HT=0.54). Dorsal side of head with dense and fine micropunctures ( Fig. 3). Dense pale grey pubescence behind eyes. Three postocular setae visible on each side, additional seta on hind margin of eye absent. Mandibles with two sharp teeth ( Fig. 4). Maxillary palpi with terminal segment relativelly narrow, pubescent, asymmetric, wider and markedly longer than glabrous penultimate segment which is triangular ( Fig. 5). First segment of antenna nearly as long as next four; segments 1 to 6 elongate, segment 5 markedly longer than wide (R=1.21–1.64, M=1.43, HT=1.43), segments 7–8 about as long as wide, segment 9 markedly transverse, segment 10 markedly transverse (R=0.57–0.70, M=0.63, HT=0.65).

Pronotum slightly transverse (R=1.08–1.16, M=1.12, HT=1.08) markedly widened behind with sides slightly rounded, widest in basal half ( Fig. 2), shining, with micropunctures slightly finer and sparser than those on head. One pair of dorsal setae and one pair of lateral setae. Marginal setae short. Elytra transverse (R=1.43–1.51, M=1.47, HT=1.43) with short, pale, but not shining pubescence arising from dense aspirate punctures. Apical fringe of bristles slightly longer than pubescence on other parts of the elytra. Abdominal tergites with short, moderately dense pubescence arising from aspirate punctures finer and sparser than on elytra.

Meso- and metatarsi with long empodial setae ( Figs. 9, 10).

Male (n=6). Sternite 9 long and narrow ( Fig. 19), apex of tergite 10 rounded with very long apical setae ( Fig. 18). Aedeagus ( Figs. 6–8, 11–17) 0.91–0.97 mm long (M= 0.93 mm, HT= 0.92 mm). Parameres bilobed, lobes widely separated, sensory pegs confusedly arranged right at apex ( Fig 17). Median lobe of aedeagus markedly overreaching paramere, apex broadly rounded ( Figs. 8, 13–15, 17).

Female. Tergite 10 with apicolateral emarginations, sharply pointed ( Fig. 20), valves as in Fig. 21.

Differential diagnosis. Acylophorus tristis differs from all hirtherto known Afrotropical species of A. densipennis group by the median lobe markedly overreaching the paramere, and by widely separated lobes of the paramere.

Distribution. The species is distributed in East, Central, South-East and West-Madagascar ( Fig. 172).

Bionomics. Most specimens were found by treading of vegetation on stream banks and ponds in vegetation partly immersed in water (e.g. Figs. 166) or in a marsh ( Fig. 167). A teneral specimen was found in March.