Exochomoscirtes quadripartitus, Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 48-49

Exochomoscirtes quadripartitus sp. nov.

( Figs. 5J , 13A , 38 , 39 )

Type material. Holotype, male ( MNHG): “ 26 XII 1994 MAL / Pahang Prov. / Kuala Lipis” [printed label]; “leg. et coll. W. G. Ullrich / MHNG-1996” [printed label] . Paratype. Female ( MNHG): “BORNEO Sabah Mt. / Kinabalu Nat. Pk. / Poring Hot Spgs. / 485m 14–31 8. 88 / A. Smetana (B166)” [printed label] .

Diagnosis. Similar to several other uniformly brown species, males can be separated by the presence of peculiar projection on tergite 7 and the females by the morphology of prehensor ( Fig. 39 ).

Description. Holotype, male. Body oval, TL/EW 1.3, slightly flattened, covered with brownish setae. Pronotum, scutellum and elytra uniformly brown, head slightly darker. Mouthparts yellow, antennomeres 1–2 yellow, 3 brownish, 4–11 black. Ventrum brown, legs brown with darkened apical portion.

Head covered with small but dense punctures, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 1.9 wider than interocular space. Antennae filiform, antennomeres 2 and 3 of subequal lengths, antennomeres 4–11 as long as 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 diameter, anterolateral corners obtuse, slightly projecting anteriorly; lateral margins straight; posterolateral corners acute; base of pronotum subtrapezoidal, with incomplete margination along basal margin; PW/PL 2.7. Scutellum punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with slightly explanate lateral margins, and three subtle longitudinal carinae, widest in the middle, punctation stronger than on pronotum, punctures separated by ca. 0.5–1.0 diameter; humeri well marked; EL/EW 1.2; EL/PL 4.6; EW/PW 1.5.

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

Ventrites 1 and 2 with sparse setation in mesal portions, ventrite 2 with basal row of numerous big punctures. Apex of tergite 7 with a peculiar outgrowth: mesal subrectangular outgrowth is flanked by two elongated palpiform projections and deep concavities. Apex of ventrite 5 very shallowly emarginated, somewhat bisinuate.

Sternite 8 (L 0.04, W 0.24) reduced, in form of small transverse bar; sternite 9 (L 0.43, W 0.27) oval, consisting of two hemisternites, deeply emarginated at apex, with several long setae at apex. Tergite 8 (L 1.87, W 0.50) extraordinarily long, moderately sclerotized, apical portion subtrapezoidal, bearing row of relatively long setae on apical margin, apodemes very long, subparallel; tergite 9 (L 0.63, W 0.32) moderately sclerotized, with minute setae at apex, with a pair of relatively short, slightly diverging basally apodemes. Tegmen (L 0.52, W 0.47) well sclerotized, parameres long and very narrow, widened at apices, mesal process moderately wide, longer than half length of parameres. Penis (L 0.40, W 0.14) of moderate size, moderately sclerotized, pala subtriangular, elongate, parameroids much shorter than pala.

Female. Prehensor large (L 1.54), membranous, consisting of wide external theca covering narrow accordion-folded duct; bursal sclerite small (L 0.24).

Measurements. Male (n = 1): TL 4.45, PL 0.85, PW 2.30, EW 3.35, EL 3.90. Female (n = 1): TL 4.50, PW 2.35, PL 0.83, EL 4.00, EW 3.15.

Distribution. Malaysia: Pahang, N Borneo.

Etymology. Specific epithet refers to the modified apex of tergite 7, which is divided into four lobes.

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

FIGURE 39. Exochomoscirtes quadripartitus sp. nov., prehensor and bursal sclerite.