Systellus mentaweicus ( Senna, 1898 ) Maruyama & Morimoto & Bartolozzi & Sakchoowong & Hashim, 2014

Maruyama, Munetoshi, Morimoto, Katsura, Bartolozzi, Luca, Sakchoowong, Watana & Hashim, Rosli, 2014, On the myrmecophilous genus Systellus Kleine (Coleoptera: Brentidae), with systematic and biological notes on S. mentaweicus (Senna), Raffles Bulletin of Zoology 62, pp. 805-811 : 806-808

Systellus mentaweicus ( Senna, 1898) , new combination

Amorphocephalus mentaweicus Senna, 1898: 237 (original description based on male; no figure); Schönfeldt, 1908: 29 (catalogue).

Leptamorphocephalus mentaweicus: Kleine, 1918: 133 , 141 (new generic combination); Kleine, 1924: 215 (comment); Kleine, 1926: 36 (key); Kleine, 1927b: 33 (list); Kleine, 1938a: 84 (catalogue); Kleine, 1938b: 15 (key).

Paramorphocephalus mentaweicus: Damoiseau, 1979: 19 (female, head characters; new generic combination); Sforzi & Bartolozzi, 2004: 310 (catalogue).

Systellus rex Kleine, 1917a: 177 (original description based on female; figs.: antenna, head and rostrum). New synonymy

Eusystellus rex: Kleine, 1917b: 316 (new generic combination); Kleine, 1926: 35, figs. 50, 51 (male description: head and rostrum, antenna); Kleine, 1927b: 31 (catalogue); Kleine, 1938a: 79 (catalogue); Kleine, 1938b: 12 (catalogue); Damoiseau, 1979: 20, 21, figs. 22–25 (female redescription: head, rostrum and prothorax, fore leg and antenna); Alonso-Zarazaga & Lyal, 1999: 49 (catalogue); Sforzi & Bartolozzi, 2004: 321 (catalogue).

Type material. Holotype male of A. mentaweicus (MSNG) : Mentawei: Si Oban [= Indonesia, W. Sumatra, Kepulauan Mentawai, Pulau Sipora: Sioban].

Holotype female of S. rex (SDEI) : East Sumatra . Paratype female of S. rex (NBCL) : Borneo.

Other material. MALAYSIA: 1 male, Ulu Gombak ( Univ. Malaya Field Studies Centre ), 250 m alt, Selangor, 9 May 2005, M. Maruyama leg. ( KUM) ; 2 males 3 females, same data, 11 May 2005, from a nest of Camponotus (Tanaemyrmex) sp. ( KUM) ; 1 male, Balungan Camp c/o Kampung Semelor (E-shore of Lake Tasek-Temengor ), 230 m alt., Perak, 10–19 July 2007, L. Bartolozzi leg. ( MZUF) ; THAILAND: 1 male, Khao Luang National Park, 200 m alt, Nakhon Sri Thammarat, Thailand , 1 November 2010, M. Maruyama leg., at UV light ( KUM) ; 1 male, Ban Krang Camp, 350 m alt, Kaeng Krachan National Park , 7 May 2013, M. Maruyama leg., at UV light ( KUM) .

Distribution. Borneo, Sumatra, Peninsular Malaysia (new record), Thailand (new record).

Redescription. Body ( Figs. 1, 2 , 8, 9 ) chocolate brown, matt, with yellowish bifid setae on head along anterior margin, on longitudinal raised parts between sulci and underside, mesorostrum at sides and rostral apophyses at lateral surface.

Head ( Figs. 1–4 , 8–10 ) twice as long as wide including eyes (from basal constriction), with three broad longitudinal sulci on vertex, lateral sulci converging anteriad, sulci smooth, impunctate, longitudinal obtuse ridges between sulci, inner and anterior margins of eyes and anterior declivitous margin with setiferous punctures; antennae with first segment robust, second segment strongly bent, asymmetrical, third to eighth subequal in shape to one another, twice as wide as long excepting neck, ninth segment subpentagonal in dorsal aspect, as smooth as preceding segments in basal third, then pubescent to apex; prorostrum widest at apical third, impunctate excepting for ridges, mesorostrum about 1.4 times as wide as long, impunctate and smooth on median depressed area, with large setiferous punctures on lateral convex areas, becoming denser basally, rostral apophyses with dense setiferous punctures on external surfaces, underside of head with scattered large setiferous punctures; underside of rostrum produced ventrally in arcuate longitudinal carina (in lateral view), sides of carina strongly compressed longitudinally, with large and smooth lateral depression distally on each side.

Pronotum ( Figs. 1 , 8 ) 1.25 times as long as wide, apical and basal margins subequal in width, disc with sparse and small punctures and short dark pubescence, with faint median groove and two pairs of faint, broad longitudinal depressions.

Elytra ( Figs. 1 , 8 ) 2.4 times as long as pronotum, striae very narrow, with row of small punctures, intervals depressed in entire length, smooth, costate on each side, first to sixth intervals reaching base, seventh and eighth intervals conjoined behind humeral callus, ninth and tenth intervals and striae obsolete at base leaving smooth surface below humeral callus; apical area weakly expanded and obtusely triangular at each apex.

Legs ( Figs. 1, 7 , 8 ) robust; femora weakly dilated to middle, depressed, then weakly swollen to flattened apical margin; tibiae bisinuate internally, broadly depressed on each side of swollen area at middle.

Body length: 10.7–15.2 mm (including rostrum).

Figures

Figs. 1–7. Systellus mentaweicus, male (from Ulu Gombak, Selangor, Peninsular Malaysia): 1, Habitus, dorsal view; 2, ditto, ventral view; 3, head, dorsal view; 4, ditto, ventral view; 5, left antenna; 6, umbilicate pores on right elytra; 7, right fore leg. Scale bars = 1.0 mm.

Figs. 8–10. Systellus mentaweicus, female (from Ulu Gombak, Selangor, Peninsular Malaysia): 8, Habitus, dorsal view; 9, ditto, ventral view; 10, head, ventral view. Scale bars = 1.0 mm.