Exochomoscirtes globosus, Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 61-63

Exochomoscirtes globosus sp. nov.

( Figs. 13K , 49 , 50 )

Holotype, male ( EUM): “ Dolok Barus Sibo- / langit N. Sumatra / 17.IX.1998 / H. Takizawa ” [printed label] . Paratype, female ( EUM): “ Kota Cane , Aceh / N. Sumatra / 26–28 IV 1998 / H. Takizawa ” [printed label] .

Diagnosis. The species resembles E. sphaericus (Champion) in external features, although it lacks a metallic hue. The distinctive features of E. globosus sp. nov. are the convex scutellum and depressed adscutellar portion of elytra. The morphology of the penis and tegmen ( Fig. 49D–E ) allow certain identification.

Description. Holotype, male. Body oval, TL/EW 1.1, very convex, covered with blackish suberect setae. Head, pronotum and elytra brownish-black. Antennomeres 1–3 yellowish, remaining dark brown. Mouthparts brownish, legs brown, apices of hind femora black.

Head with distinct punctation, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 1.9 X wider than interocular space. Antennae subserricorn, antennomeres 8–11 absent in the holotype. Antennomere 3 distinctly smaller than antennomere 2, antennomeres 4–8 triangular, flattened, distinctly longer than antennomeres 2 and 3 combined. Palpomeres of maxillary palpi moderately widened.

Pronotum slightly convex, covered with subtle, sparse punctation, punctures shallow, separated by 2.0– 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 3.4. Scutellum relatively big, convex, punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with slightly explanate lateral margins, depressed in adscutellar area, widest in the middle, punctation stronger than on pronotum, sparse, punctures separated by ca. 2.0–4.0 diameters; humeri well marked; apices of elytra slightly triangularly explanate, EL/EW 1.0; EL/PL 5.2; EW/PW 1.6.

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

Apex of tergite 7 unmodified. Apex of ventrite 5 slightly emarginated.

Sternite 9 (L 0.60, W 0.35) elongated, subtriangular, with relatively long setae at apex. Tergite 8 (L 0.70, W 0.63) moderately sclerotized, apical portion subtrapezoidal, bearing row of short setae on apical margin, apodemes relatively short, diverging basally; tergite 9 (L 0.65, W 0.54) moderately sclerotized, with very small subquadrate apical portion without setae at apex, with a pair of relatively short, diverging apodemes. Tegmen (L 0.72, W 0.57) well sclerotized, parameres straight, relatively wide, apices of parameres with 2–3 denticles on mesal edge, mesal process moderately wide, as long as 0.7 length of parameres. Penis (L 0.60, W 0.17) relatively long, pala elongated, trigonium short, parameroids moderately wide, as long as pala.

Female. Antennomeres 4–11 less widened, palpomeres of maxillary palpi very wide. Prehensor with very short (L = 0.12) and lightly sclerotized tubular portion.

Measurements. Male (n = 1): TL 4.67, PL 0.80, PW 2.68, EL 4.18, EW 4.15. Female (n = 1): TL 5.20, PL 1.00, PW 3.05, EL 4.65, EW 4.60.

Distribution. Borneo.

Etymology. Lat. globosus = spherical, refers to the globose body.

Figures

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 49. Exochomoscirtes globosus sp. nov. A) sternite 9; B) tergite 8; C) tergite 9; D) tegmen; E) penis. Scale bar = 0.5 mm.

FIGURE 50. Exochomoscirtes globosus sp. nov., female, prehensor.