Exochomoscirtes nigromarginatus, Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 58-59

Exochomoscirtes nigromarginatus sp. nov.

( Figs. 3D , 5I , 13I , 47 )

Type material. Holotype, male ( DBET): “ Malaysia, Pahang prov. / Taman Negara N.P. / Kuala Tahan, 14.3.2007, / lgt. Jiři Foit” [printed label].

Diagnosis. Body shape is similar to E. bezdeki sp. nov., but the dorsum is redish-brown with black margination on elytra (entirely black in E. bezdeki ). Exochomoscirtes nigromarginatus sp. nov. can be distinguished from E. bezdeki sp. nov. on the basis of the morphology of the tegmen, which has strongly widened parameroids (slightly widened in E. bezdeki sp. nov.).

Description. Holotype, male. Body oval, TL/EW 1.3, slightly flattened, covered with brownish setae. Head brown, anterior portion dark brown, pronotum brown with brownish-black margins, elytra brown with blackish margins. Mouthparts and antennae yellow. Ventrum brown, legs brown with the exception of apices of metafemora, which are darkened, brownish black.

Head covered with small but dense punctures, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 2.0 X wider than interocular space. Antennae filiform, antennomeres 9–11 missing in the holotype. Antennomeres 2 and 3 of subequal lengths, antennomeres 4–11 slightly longer than antennomeres 2 and 3 combined. Palpomeres of maxillary palpi slightly widened.

Pronotum slightly convex, covered with distinct punctation, stronger than on head, separated by ca. 1.0 (rarely 2.0) diameters, anterolateral corners almost right-angled, slightly obtuse, projecting anteriorly; lateral margins straight; posterolateral corners acute; base of pronotum subtrapezoidal, with incomplete margination along basal margin; PW/PL 3.0. Scutellum 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 than on pronotum, punctures separated by ca. 1.0 diameter; humeri well marked; EL/EW 1.1; EL/PL 4.9; EW/PW 1.5.

Legs moderately long. Hind tibial spurs well developed, dorsal one curved, as long as 2/3 length of tarsomere 1, and nearly twice as long as ventral one, slightly widened subapically, forming small, flattened lobe; ventral spur slightly curved. Tarsomere 1 of posterior legs widened apically, with bulbous, microreticulated dorsal portion.

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 shallowly emarginated, bisinuate.

Sternite 8 (L 0.12, W 0.29) widely U-shaped; sternite 9 (L 0.82, W 0.38) subtriangular, emarginated at apex, apodemes fused basally, with several very short setae at apex. Tergite 8 (L 1.60, W 1.20) large, moderately sclerotized, with arcuate apical margin, bearing row of moderately long setae on apical margin, apodemes long, diverging basally; tergite 9 (L 0.98, W 0.65) moderately sclerotized, apical portion small, with short setae at apex, with a pair of apodemes diverging basally. Tegmen (L 0.87, W 0.73) well sclerotized, parameres strongly widened apically, mesal process narrow, as long as half length of parameres. Penis (L 0.45, W 0.16) small, moderately sclerotized, pala subtriangular, apical processes almost as long as pala.

Female unknown.

Measurements. Male (n = 1): TL 4.64, PL 0.85, PW 2.55, EL 4.15, EW 3.70.

Distribution. Pahang, Malaysia.

Etymology. Specific epithet referring to dark margination of elytra.

Figures

FIGURE 3. Metatibial spurs in Exochomoscirtes. A) E. dilaticornis sp. nov.; B) E. discoidalis (Pic); C) E. longispinus sp. nov.; D) E. nigromarginatus sp. nov.; E) E. picturatus sp. nov.; F) E. takizawai sp. nov.

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