Exochomoscirtes sphaericus ( Champion, 1918 ) Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 60-61

Exochomoscirtes sphaericus ( Champion, 1918) comb. nov.

Scirtes sphaericus Champion, 1918: 197

( Figs. 10H , 13J , 48 )

Type material. Holotype, male ( NHM): “ Mt. Matang , / W. Sarawak. / G. E. Bryant. / 13.2.14. / 1000m ” [printed & handwritten label]; “H63” [handwritten label]; “ ♂ ” [printed label]; “Type / H.T.” [round label with red margin]; “ Scirtes / sphaericus / Ch” [handwritten by Champion].

Additional material studied. Male ( NHM): “ BRUNEI: E115 7’ N4 34’ / Kuala Belalong FSC / Dipterocarp forest / Dryobalanops beccarii / BM(NH) 1991-173” [printed label]; “ Aerial Malaise 1A / 260m alt. 8.vi.91 / N. Mawdsley NM182” [printed label]; “3131” [printed pink label] .

Diagnosis. Species similar to E. globosus sp. nov., but differing in having distinct metallic hue and flat scutellum. Certain identification is possible on the basis of male genital features ( Fig. 48 ).

Redescription. Holotype, male. Body oval, TL/EW 1.1, very convex, covered with blackish suberect setae. Head, pronotum and elytra black with distinct greenish metallic hue. Antennae and mouthparts brown, legs yellowish-brown.

Head with distinct punctation, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 1.8 X wider than interocular space. Antennae filiform, antennomeres 9–11 absent in the holotype. Antennomeres 2 and 3 of subequal lengths, antennomeres 4–9 slightly shorter than antennomeres 2 and 3 combined. Palpomeres of maxillary palpi moderately widened.

Pronotum slightly convex, covered with distinct but sparse punctation, punctures shallow, separated by 1.0–3.0 diameters, anterolateral corners somewhat obtuse, projecting anteriorly; lateral margins straight; posterolateral corners acute; base of pronotum subtrapezoidal, without margination along basal margin; PW/PL 2.9. Scutellum relatively big, somewhat depressed, punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with slightly explanate lateral margins, widest in the middle, punctation stronger and slightly denser than on pronotum, punctures separated by ca. 2.0 diameters; humeri well marked; apices of elytra slightly triangularly explanate, EL/EW 0.9; EL/PL 4.7; EW/PW 1.6.

Legs moderately long. Hind tibial spurs well developed, dorsal one almost straight, as long as 2/3 length of tarsomere 1, and almost twice as long as ventral one; ventral spur almost straight.

Ventrite 1 with sparse setation in mesal portion, ventrite 2 with basal row of big punctures. Apex of tergite 7 unmodified. Apex of ventrite 5 regularly rounded. Mesal portion of ventrite 5 with impunctate, somewhat depressed area.

Sternite 8 (L 0.23, W 0.38) small, widely U-shaped; sternite 9 (L 0.83, W 0.34) elongated, subrectangular, with relatively long setae at apex. Tergite 8 (L 0.95, W 0.48) moderately sclerotized, apical portion subrectangular, bearing row of relatively short setae on apical margin, apodemes relatively short, slightly diverging basally; tergite 9 (L 1.00, W 0.82) moderately sclerotized, with very small apical portion and minute setae at apex, with a pair of relatively long, strongly diverging apodemes. Tegmen (L 0.90, W 0.50) well sclerotized, parameres straight, slightly widened at apices, each paramere with a small process near its base, apices of parameres inwardly hooked, mesal process moderately wide, as long as 0.8 length of parameres. Penis (L 0.64, W 0.15) relatively long, pala elongated, trigonium short, parameroids very narrow, shorter than pala.

Female unknown.

Variability. Species strongly varying in size.

Measurements. Males (n = 2): TL 3.85–4.70, PL 0.75–0.90, PW 2.20–2.65, EL 3.40–4.25, EW 3.65– 4.28.

Distribution. Borneo.

Remarks. Champion (1918) mentioned the close affinity of Exochomoscirtes sphaericus to Scirtes caeruleus Champion from Panama. Scirtes caeruleus is indeed externally very similar to E. sphaericus , but due to several differences (very narrow, laminate mesoventral process, different morphology of prehensor) is not transferred to Exochomoscirtes .

Figures

FIGURE 10. Selected holotype labels. A) Exochomoscirtes bimaculatus Pic; B) E. binotatus Pic; C) E. decemguttatus (Champion); D) E. ephippiatus (Champion); E) E. maculatus (Bourgeois); F) E. maculatus (Waterhouse); G) E. rufomaculatus Pic; H) E. sphaericus (Champion); I) E. tetrastigma (Champion).

FIGURE 13. Habitus illustrations of Exochomoscirtes. A) E. quadripartitus sp. nov.; B) E. discoidalis (Pic), male; C) E. discoidalis (Pic), female; D) E. thailandicus sp. nov.; E) E. serricornis sp. nov.; F) E. cambodiensis sp. nov.; G) E. bezdeki sp. nov., male; H) E. bezdeki sp. nov., female; I) E. nigromarginatus sp. nov.; J) E. sphaericus (Champion); K) E. globosus sp. nov.; L) E. buechei sp. nov.; M) E. dilaticornis sp. nov., male. Scale bar = 2.0 mm.

FIGURE 48. Exochomoscirtes sphaericus (Champion), male. A) sternite 8; B) sternite 9; C) tergite 8; D) tergite 9; E) tegmen; F) penis. Scale bar = 0.5 mm.