Exochomoscirtes tetrastigma ( Champion, 1918 ) Ruta & Yoshitomi, 2010

Ruta, Rafał & Yoshitomi, Hiroyuki, 2010, Revision of the genus Exochomoscirtes Pic (Coleoptera: Scirtidae: Scirtinae) 2598, Zootaxa 2598 (1), pp. 1-80 : 32-34

Exochomoscirtes tetrastigma ( Champion, 1918) comb. nov.

Scirtes tetrastigma Champion, 1918: 221

( Figs. 10I , 11M , 24 , 25 )

Type material. Holotype, male ( NHM): “Type / H. T.” [round label with red margin]; “6III5” [handwritten]; “ Assam / Patkai Mts” [printed label]; “Doherty” [printed label]; “ Scirtes / tetrastigma” [handwritten by Champion ]; “Fry Coll. / 1905.100” [printed label].

Additional material studied. Male ( NHM): “NE INDIA, MEGHALAYA, / SW of CHERRAPUNJEE / 25°13’–14’ N 91°40’ E, 900m / L. Dembický leg., 1.–24.v.2005 ” [printed label]. Female ( NMW): “NE- INDIA: Meghalaya / W Garo Hills / Nokrek NP; ca. 1100m ” [printed label]; “25°29.6’ N 90°19.5’ E / 9.– 17.5.1996 / leg. Jendek & Sausa” [printed label] .

Diagnosis. Species with unique dorsal pattern with four regularly oval black maculae on yellow dorsum. Dorsal metatibial spur is characteristically widened and hooked in males.

Redescription. Male. Body oval, TL/EW 1.4, convex, covered with yellowish setae. Head and pronotum yellow, elytra yellow with two large black oval areas on each elytron: somewhat transverse one in basal half of elytra and a second, more oval one, in posterior portion of elytra. Antennae yellowish, slightly darkened apically, mouthparts, legs, and abdomen yellowish, posterior femora slightly darkened, yellowish-brown.

Head with distinct punctation, punctures separated by ca. 1.0 diameter. Eyes big, protuberant; head 1.6 X wider than interocular space. Antennae filiform, reaching basal 1/3 of elytra. Antennomeres 2 and 3 of subequal lengths, antennomeres 4–11 slightly shorter than antennomeres 2 and 3 combined. Palpomeres of maxillary palpi moderately widened.

Pronotum slightly convex, covered with subtle, sparse punctation, punctures separated by 1.0–3.0 diameters, anterolateral corners obtuse, slightly projecting anteriorly; lateral margins straight; posterolateral corners acute; base of pronotum subtrapezoidal, with complete margination along basal margin; PW/PL 3.1. Scutellum relatively big, punctured as on pronotum, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline.

Elytra oval, with slightly explanate lateral margins, widest at the middle, punctation stronger and slightly denser than on pronotum, punctures separated by ca. 1.0 diameter; humeri well marked; EL/EW 1.1; EL/PL 4.8; EW/PW 1.4.

Legs moderately long. Hind tibial spurs well developed, dorsal one as long as tarsomere 1, wide and hooked apically, with minute denticles on inner margin; ventral spur almost straight, slightly longer than half length of longer spur.

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 0.42, W 0.39) wide, oval, with moderately long setae at apical margin. Tergite 8 (L 0.73, W 0.42) moderately sclerotized, apical portion subtrapezoidal, bearing relatively long setae on apical margin, apodemes subparallel; tergite 9 (L 0.38, W 0.36) small, moderately sclerotized, with very small apical portion and minute setae at apex, with a pair of short, strongly diverging apodemes. Tegmen (L 0.55, W 0.44) well sclerotized, parameres straight, inwardly hooked at apices, apices tridentate, mesal process very narrow, as long as 0.7 length of parameres. Penis (L 0.35, W 0.15) small, pala subtriangular, with two short lateral processes at apex, and very narrow parameroids, which are shorter than pala.

Female. Metatibial spurs subtly modified, longer spur abruptly hooked at apex, as long as tarsomere 1, ventral spur 0.5 length of dorsal spur. Prehensor (L 0.92) long.

Variability. Males: TL/EW 1.3–1.4.

Measurements. Males (n = 2): TL 3.35–3.37, PL 0.58–0.65, PW 1.75–1.85, EL 2.80–2.95, EW 2.49– 2.68. Female (n = 1): TL: 3.02, PL 0.63, PW 1.65, EL 2.65, EW 2.30.

Distribution. India: Assam, Meghalaya.

Figures

FIGURE 10. Selected holotype labels. A) Exochomoscirtes bimaculatus Pic; B) E. binotatus Pic; C) E. decemguttatus (Champion); D) E. ephippiatus (Champion); E) E. maculatus (Bourgeois); F) E. maculatus (Waterhouse); G) E. rufomaculatus Pic; H) E. sphaericus (Champion); I) E. tetrastigma (Champion).

FIGURE 11. Habitus illustrations of Exochomoscirtes. A) E. bimaculatus Pic; B) E. basipunctatus sp. nov.; C) E. binotatus Pic; D) E. rufomaculatus Pic; E) E. ephippiatus (Champion); F)–I) E. picturatus sp. nov., color forms; J)–L) E. takizawai sp. nov., color forms; M) E. tetrastigma (Champion). Scale bar = 2.0 mm.

FIGURE 24. Exochomoscirtes tetrastigma (Champion), male. A) sternite 9; B) tergite 8; C) tergite 9; D) tegmen; E) penis. Scale bar = 0.5 mm.

FIGURE 25. Exochomoscirtes tetrastigma (Champion), female genitalia.