Exochomoscirtes jaechi, Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 45-46

Exochomoscirtes jaechi sp. nov.

( Figs. 5C , 12M , 35 )

Type material. Holotype, male ( NMW): “NW-THAIL.: Chiang Mai / 98°57’ E 18°49’ N, Zoo / 21.– 28.12.1987 Malicky / & Chantaramongkol LF” [printed label] . Paratypes. Male ( NMW): same data as holotype, but 6– 12.12.1988. Male ( NMW): “NW THAILAND / Chiang Mai (Zoo) / 9.– 16.5.1988 / leg. Malicky (Licht)” [printed label]. Male ( EUM): “Nha Hin, alt. 210 / N18°10’, E104°30’ / Bolixhamxai Prov. / Laos; 6~ 8-XI-2004 / T. Niisato leg.” [printed label]; “genitalia on slide / No. HY 972” [printed 7 handwritten label] .

Diagnosis. The species externally resembles E. luteosuturalis , but dorsal pattern is less contrasting. Sternite 9 in E. jaechi is narrow, parallel-sided with bisipinose apex; in E. luteosuturalis it is broader, oval and without apical projections.

Description. Holotype, male. Body elongate oval, TL/EW 1.5, slightly flattened, covered with brownish setae. Head, pronotum and scutellum brown, elytra brown with faint pattern consisting of oval basal spot and elongate adsutural macula in posterior half of elytra. Mouthparts, antennae, and legs yellowish, metafemora darkened, brown. Ventral portion brown.

Head with distinct punctation, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 2.0 X wider than interocular space. Antennae filiform. Antennomere 1 subcylindrical, antennomeres 2 and 3 of subequal lengths, antennomeres 4–11 as long as antennomeres 2 and 3 combined. Palpomeres of maxillary palpi moderately widened.

Pronotum moderately convex, covered with distinct punctation, stronger than on the head, separated by ca. 1.0 (rarely 2.0) diameters, anterolateral corners obtuse, slightly projecting anteriorly; lateral margins subtly rounded; posterolateral corners acute; base of pronotum bisinuate, with complete margination along basal margin; PW/PL 2.6. Scutellum punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with faint marks of two longitudinal ridges, slightly explanate lateral margins, widest at the basal 1/3, punctation as on pronotum, punctures separated by ca. 1.0 diameter; humeri well marked; EL/EW 1.3; EL/PL 4.8; EW/PW 1.4.

Legs moderately long. Hind tibial spurs well developed, dorsal one curved, unmodified, as long as 3/4 length of tarsomere 1, and over 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.

Sternite 9 (L 0.41, W 0.09) elongated, with subparallel sides, apex with long, narrow denticles. Tergite 8 (L 0.82, W 0.45) moderately sclerotized, apical portion subtrapezoidal, bearing indistinct setae on apical margin, apodemes moderately long, diverging basally; tergite 9 (L 1.15, W 0.28) very long, moderately sclerotized, with relatively wide apical portion and minute setae at apex, with a pair of moderately short apodemes, not diverging basally. Tegmen (L 0.65, W 0.14) long, large, slightly sclerotized, parameres sinuate, slightly narrowing to apices, mesal process relatively wide, somewhat widened at apex, almost as long as parameres. Penis (L 0.47, W 0.11) small, pala elongate, parameroids shorter than pala, mesal process short, distinctly shorter than parameroids.

Female unknown (see note under E. luteosuturalis description).

Variability. TL/EW 1.4–1.5 (1.5).

Measurements. Males (n = 3): TL 3.35–4.25 (3.72), PW 1.75–2.10 (1.87), PL 0.60–0.80 (0.68), EL 3.00– 3.80 (3.30), EW 2.35–2.90 (2.57).

Distribution. Thailand, Chiang Mai, Laos.

Etymology. Dedicated to Dr. Manfred Jäch (NMW), who kindly allowed us to study interesting material deposited in NMW.

Figures

FIGURE 5. Abdominal details in Exochomoscirtes. A) E. dilaticornis sp. nov., ventrite 5; B) E. discoidalis (Pic), ventrite 5; C) E. jaechi sp. nov., tergite 7; D) E. klausnitzeri sp. nov., tergite 7; E) E. luteosuturalis sp. nov., tergite 7; F) E. luteosuturaloides sp. nov., tergite 7; G) E. maculatus (Waterhouse), abdomen; H) E. maculatus (Waterhouse), ventrites 3–5; I) E. nigromarginatus sp. nov., ventrite 5; J) E. quadripartitus sp. nov., tergite 7.; K) E. ruforotundus (Watts) (Australia), tergite 7; L) E. takizawai sp. nov., ventrite 5.

FIGURE 12. Habitus illustrations of Exochomoscirtes. A) E. maculatus (Waterhouse); B)–C) E. ceylonicus sp. nov.; D) E. decemguttatus (Champion); E)–G) E. klausnitzeri sp. nov., color forms F – S Thailand, male, E and G – Sarawak, females; H) E. cf. klausnitzeri (NW Thailand); I) E. luteosuturalis sp. nov.; J) E. cf. luteosuturalis sp. nov., female, Sulawesi; K) E. cf. luteosuturalis, female, Vietnam; L) E. luteosuturaloides sp. nov.; M) E. jaechi sp. nov.; N) E. ruforotundus (Watts); O) E. ruforotundus (Watts), Bali. Scale bar = 2.0 mm.

FIGURE 35. Exochomoscirtes jaechi sp. nov., male. A) sternite 9, closeup; B) sternite 9; C) tergite 8; D) tergite 9; E) tegmen; F) penis. Scale bar = 0.5 mm (with the exception of A).