Exochomoscirtes serricornis, Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 54-55

Exochomoscirtes serricornis sp. nov.

( Figs. 13E , 43 )

Type material. Holotype, male ( NHMB): “ MALAYSIA, PAHANG, 2003 / Cameron Highlands ; / TANAH RATA, 1500–1700m; / P. Pacholatko leg. 1.–13.ii.” [printed label].

Diagnosis. Depressed black body may resemble E. bezdeki , from which E. serricornis differs in its smaller body, serrate antennae and distinctive tegmen with subparallel apical portion armed with minute denticles on inner margins. E. cambodiensis is similar, but has more oval body and is distinctly smaller.

Description. Holotype, male. Body oval, TL/EW 1.45, flattened, covered with dark brown setae. Head, pronotum and elytra brownish-black, scutellum slightly lighter, dark brown. Antennomeres 1–3, mouthparts, anterior and middle legs light brown, posterior legs dark brown. Antennomeres 4–10 black. Ventral portion dark brown.

Head with distinct punctation, punctures separated by ca. 1.0–2.0 diameters. Eyes big, protuberant; head 1.9 X wider than interocular space. Antennae serrate, apical antennomere absent in the holotype. Antennomere 1 cylindrical, 2 globular, 3 strongly reduced, minute, much shorter than antennomere 2, antennomeres 4– 10 dilated, triangular, almost as long as antennomeres 1–3 combined. Palpomeres of maxillary palpi only slightly widened.

Pronotum slightly convex, covered with distinct punctation, a bit stronger than on head, separated by ca. 1.0 diameter, anterolateral corners obtuse, slightly projecting anteriorly; lateral margins slightly rounded; posterolateral corners acute; base of pronotum bisinuate, with subtle, complete margination along basal margin; PW/PL 3.1. Scutellum punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with three longitudinal ridges, and explanate lateral margins, widest at the basal 1/3, punctation stronger than on pronotum, punctures separated by ca. 0.5–1.0 diameter; humeri well marked; EL/EW 1.3; EL/PL 5.7; EW/PW 1.4.

Legs moderately long. Hind tibial spurs well developed, dorsal one slightly curved, unmodified, as long as 2/3 length of tarsomere 1, and almost 2.5 X longer than ventral one; ventral spur almost straight.

Ventrite 1 with sparse setation in mesal portion, longitudinal ridge present in basal portion of ventrite 1, ventrite 2 with basal row of big punctures. Apex of tergite 7 unmodified. Apex of ventrite 5 slightly emarginated.

Sternite 9 (L 0.43, W 0.29) elongated, consisting of two subtriangular hemisternites, with indistinct setae on apical margin. Tergite 8 (L 0.53, W 0.40) well sclerotized, apical portion subtrapezoidal, apical margin arcuate, bearing distinct setae on apical margin, apodemes short, slightly diverging basally; tergite 9 (L 0.40, W 0.47) small, moderately sclerotized, with narrow apical portion and indistinct setae at apex, with a pair of moderately short apodemes, strongly diverging basally, fused in anterior portion. Tegmen (L 0.53, W 0.31) large, well sclerotized, parameres arcuate, narrow, slightly widening towards apices, apices rounded, interior portion with a row of denticles, mesal process narrow, moderately long, exceeding half of the length of parameres. Penis (L 0.38, W 0.12) small, pala pear-shaped, parameroids indistinct, mesal process absent.

Female unknown.

Measurements. Male (n = 1): TL 3.85, PL 0.60, PW 1.85, EL 3.40, EW 2.65.

Distribution. Known only from the locus typicus in Malaysia (Pahang).

Etymology. Specific epithet refers to serrate antennae.

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 43. Exochomoscirtes serricornis sp. nov., male. A) sternite 9; B) tergite 8; C) tergite 9; D) tegmen; E) penis. Scale bar = 0.5 mm.