Scirtes evansi Pic, 1932

Ruta, Rafał & Kiałka, Agata, 2021, The genus Scirtes Illiger of Fiji (Coleoptera: Scirtoidea: Scirtidae), Zootaxa 4926 (4), pp. 501-520 : 502-505

= Scirtes evansi Pic, 1932 syn. nov.

( Figs 1A , 2A, 2C , 3 , 4 A–J, 5)

Scirtes natovensis Champion, 1919: 27 (locus typicus: Natova)

Scirtes evansi Pic, 1932: 210 (locus typicus: Taveuni, Waiyevo)

Type material. Scirtes natovensis Champion, 1919 : Lectotype, here designated, male ( NHM): “ FIJI. / NATOVA. / IV.1918 / R. VEITCH” [printed label], “ Scirtes / natovensis” [handwritten by Champion], “Type / H. T.” [round label with red margin, printed], “Pres. by / Imp. Bur. Ent.” [printed], “1919-246” [printed] ( Fig. 2C ). Scirtes evansi Pic, 1932 : Lectotype, here designated, male ( NHM): “ FIJI IS. / Teveuni. / Waiyevo. / 15.VI.24. / at light / Dr. H. S. Evans / 1686.24” [printed & handwritten], “Pres. by / Imp. Inst. Ent. / Brit. Mus. / 1932-295.” [printed], “gardés” [handwritten by Pic], “ Scirtes / evansi nsp” [handwritten by Pic] ( Fig. 2A ); paralectotype, here designated, male ( MNHN): “ FIJI IS. / Taveuni / nr Waiyewo. / 1000 ft / 9.III.24 / Dr. H. S. Evans” [handwritten & printed], “ Scirtes / Evansi n sp” [handwritten by Pic].

Additional material studied. 1 male ( BPBM): FIJI: Kadavu , Kadavu Prov., 0.25km SW Solodamu Village, Moanakaka Bird Sanctuary, 60m, -19.078, 178.121, Malaise: M02, 11.IV.–2.V.2004, S. Lau, FBA202789 ; 3 males ( BPBM): same data as above but Malaise : M04, 15.II–7.III.2004, S. Lau, FBA202525, FBA202526 and FBA202527 ; 1 male ( BPBM): FIJI: Taveuni , Cakaudrove Prov., 5.6 km SE Tavuki Village, Devo Peak, 1187m, - 16.843, -179.955, 24.X.2002 – 31.X.2002, Malaise: M01, E.I. Schlinger, M. Tokotaa, FBA201205 ; 1 male ( BPBM): FIJI: Viti Levu , Naitasiri Prov., 4.8km N Veisari, logging rd. to Waivudawa, 300m, -18.075, 178.362, 12.XII.2002 – 3.1.2003, Malaise: M01, E.I. Schlinger, M. Tokotaa, FBA201713 ; 1 female ( BPBM): same data as above but FBA201712 ; 1 female ( BPBM): FIJI: Viti Levu , Vuda Prov. , Koroyanitu EcoPrak , Mt. Evans Range, 1 km E Abaca Village, Savuione Trail, 800m, 6.III.–11.III.2003, Malaise trap: M01, E. I. Schlinger, L. Tuimerke, -17.667, 177.55, FBA_221279 ; 1 female ( BPBM): FIJI: Viti Levu , Naitasiri Prov. , 4 km WSW Colo-i-Suva Village, Mt. Nakobalevu, 372m, 14.XI.–24.XII.2003, Malaise trap: M03, E. I. Schlinger, Timoci, -18.055, 178.424, FBA_221571 ; 1 male ( NHM): R. A. LEVER, C FIJI 1227, Korovou [?, handwritten], 23.8.41, Pres. by Comm Inst Ent, B. M. 1981–315 ; 2 females ( NHM): R. A. LEVER, C FIJI 1126, Tailevu , 31.3.41, Pres. by Comm Inst Ent, B. M. 1981–315, one with additional label Scirtes, Det. G. E. Bryant .

Diagnosis. The largest Fijian Scirtes (TL 3.3–4.0 mm), body light brown; aedeagus symmetrical, parameres narrow, as long or longer than basal portion of tegmen.

Redescription. Lectotype, male. Body oblong oval, moderately convex, covered with yellowish suberect setae. Dorsum yellowish-brown.

Head covered with dense and strong punctures, separated by ca. 0.3–0.5 diameter. Eyes big, moderately protuberant; head 1.8× wider than interocular space. Antennae filiform, antennomeres 1 & 2 subcylindrical, antennomere 3 subconical, very narrow, remaining antennomeres wider, subconical. Pronotum slightly convex, covered with dense punctures, punctures separated by ca. 0.5–1.0 diameter, anterolateral corners slightly projecting anteriorly, obtuse; lateral margins subtly rounded; posterolateral corners almost right-angled; base of pronotum bisinuate, margination along basal margin well visible. Scutellar shield equilaterally triangular, punctured similarly to pronotum, but punctures shallower. Angle between pronotum and elytra not marked in dorsal outline. Elytra broadly oval, without traces of longitudinal ridges, widest in the middle, punctation sparser than on pronotum, distance between punctures ca. 1.0 diameter; humeri well marked. Hind tibial spurs well developed, longer spur curved, as long as 2/3 length of tarsomere 1, shorter spur slightly curved, as long as 1/2 of the length of longer spur. Ventrites 1 and 2 covered with sparse setation, ventrites 2–4 with mesal areas devoid of punctures. Ventrite 2 with two mesal pores ( Figs 3 A–B). Apex of ventrite 5 widely rounded.

Sternite VIII (L 0.26 mm, W 0.07 mm) small, widely U-shaped ( Fig. 4B ). Sternite IX (L 0.16 mm, W 0.18 mm) Y-shaped, covered with sparse setae on margin of apices of lateral portions ( Fig. 4C ). Tergite VIII (L 0.43 mm, W 0.42 mm) large, with transversely rectangular apical portion, apical margin with short setae, apical portion of plate with sparse longer setae, apodemes relatively short, as long as apical plate ( Fig. 4D ); tergite IX (L 0.38 mm, W 0.28 mm) with small, transversely rectangular apical plate, apodemes longer than apical plate, diverging ( Fig. 4E ). Aedeagus symmetrical. Tegmen (L 0.65 mm, W 0.21 mm) large ( Figs 4 F–G), parameres very narrow, widened at base, subparallel and pointed at apices, basal portion oval, shorter than parameres. Penis (L 0.43 mm, W 0.12 mm) slightly more than half as long as tegmen ( Figs 4 H–J), with big, oblong oval pala and short, apical process pointed and hooked in lateral view.

Female. Externally indistinguishable from male. Prehensor small (L 0.48 mm, W 0.27 mm), variable in shapefrom subtriangular to subrectangular, always with tubercle-like process, bursal sclerite small (L 0.18 mm, W 0.31 mm), ring-shaped, subtrapezoidal, accessory gland large, S-shaped, its posterior portion with net-like structure, covered with short, straight setae ( Fig. 5 ).

Variability. TL variable, ca. 3.3–4.0 mm, females usually larger; coloration of dorsum not always uniformly brown; in some specimens margins of pronotum, scutellar shield, humeri and adsutural portion of elytra are light yellow, and remaining part of pronotum and elytra are darker, brown.

Measurements and ratios. Males (n=4): TL 3.30–3.75 mm (3.53 mm), EL 2.75–3.20 mm (2.98 mm), PL 0.60–0.70 mm (0.65 mm), EW 2.20–2.60 mm (2.40 mm), PW 1.60–1.85 mm (1.73 mm), TL/EW 1.44–1.55 (1.51), PW/PL 2.46–2.67 (2.59), EL/EW 1.23–1.32 (1.27), EL/PL 4.31–4.58 (4.56), EW/PW 1.38–1.41 (1.39); females (n=6): TL 3.40–4.0 mm (3.80 mm), EL 2.90–3.50 mm (3.24 mm), PL 0.70–0.75 mm (0.72 mm), EW 2.20–2.75 mm (2.46 mm), PW 1.60–2.00 mm (1.77 mm), TL/EW 1.45–1.63 (1.55), PW/PL 2.29–2.67 (2.46), EL/EW 1.27–1.38 (1.32), EL/PL 4.14–4.79 (4.52), EW/PW 1.37–1.43 (1.39).

Distribution. Known from Viti Levu, Kadavu, and Taveuni Islands ( Fig. 9B ).

Remarks. Study of genitalia of type specimens of Scirtes evansi allowed us to conclude that it is a junior synonym of Scirtes natovensis . According to the original description of Scirtes natovensis , more than one specimen was studied by Champion: “two specimens in fairly good condition, others rendered useless by pinning”. Although only a single specimen was found in the collection of NHM, the presence of additional ones seems plausible. The specimen from the collection of the NHM, labeled as a type, is designated here as the lectotype in order to preserve the stability of nomenclature by selecting one specimen as the sole, name-bearing type of the taxon. Scirtes evansi was described by Pic (1932) on the basis of specimens from the collection of Natural History Museum in London. According to the remark in the original description, types of S. evansi are deposited in NHM, but an additional specimen or specimens are also present in the collection of Pic (now in MNHN). The specimen of S. evansi from the collection of the NHM, labeled as a type, is designated here as the lectotype in order to preserve the stability of nomenclature by selecting one specimen as the sole, name-bearing type of the taxon. Morphology of male genitalia allow us to conclude that Champion’s assumption ( Champion 1919) according to which S. natovensis is closely related to S. sericeus Waterhouse, 1880 or S. canescens Motschulsky, 1863 was wrong (see Ruta 2008, 2009).

Figures

FIGURE 1. Scirtes spp., dorsal view of adults. A) S. natovensis Champion; B) S. navaiensis sp. nov., holotype; C) S. schlingeri sp. nov., holotype; D) S. devoensis sp. nov., holotype; E) S. humeralis Pic, male; F) S. humeralis Pic, lectotype, female; G) S. tokotaai sp. nov., paratype; H) S. veitchi Champion, lectotype, male; I) S. abacaensis sp. nov., holotype; J) S. pseudoveisariensis sp. nov., holotype; K) S. veisariensis sp. nov., holotype. Scale bar = 1.0 mm.

FIGURE 2. Type labels. A) Scirtes evansi Pic, paralectotype; B) Scirtes humeralis Pic, paralectotype; C) Scirtes natovensis Champion, lectotype; D) Scirtes veitchi Champion, holotype.

FIGURE 3. Scirtes natovensis Champion, male, abdomen. A) abdominal ventrites; B) abdominal ventrites, close-up; an arrow indicates a fovea on ventrite 2.

FIGURE 4. Scirtes spp., male genitalia (B—sternite 8; C—sternite 9; D—tergite 8; E—tergite 9; F, G, K, M—tegmen; H–J, L, N–O—penis). A–J) S. natovensis Champion; K–L) S. navaiensis sp. nov.; M–O) S. schlingeri sp. nov. Scale bar = 0.50 mm.

FIGURE 5. Scirtes natovensis Champion, female (A–C, F—Kadavu; D—Taveuni, E—Viti Levu). A) genital tract and termina- lia; B–E) close-up of prehensor and bursal sclerite; F) close-up of accessory gland. Scale bar = 0.50 mm.

FIGURE 9. Distribution of Fijian Scirtes spp. A) Scirtes humeralis Pic; B) Scirtes natovensis Champion; C) Scirtes tokotaai sp. nov.; D) remaining species.