Scirtes humeralis Pic, 1932

Ruta, Rafał & Kiałka, Agata, 2021, The genus Scirtes Illiger of Fiji (Coleoptera: Scirtoidea: Scirtidae), Zootaxa 4926 (4), pp. 501-520 : 510-512

Scirtes humeralis Pic, 1932

( Figs 1 E–F, 2B, 6C–D, 7)

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

Type material. Lectotype, here designated, female ( NHM): “ FIJI IS. / Taveuni. / nr. Waiyevo. / 1000 ft. / 9.III.24. / Dr. H. S. Evans / 886.24” [printed & handwritten], “Pres. by / Imp. Inst. Ent. / Brit. Mus. / 1932-295.” [printed], “ Scirtes / humeralis / nsp” [handwritten by Pic] ( Fig. 2B ); paralectotype, here designated, female ( MNHN): “ FIJI IS. / Taveuni / nr Waiyewo. / 1000 ft / 9.III.24 / Dr. H. S. Evans” [handwritten & printed], “voisin de / narovensis / Chp” [handwritten by Pic], “ S. humeralis / n sp” [handwritten by Pic].

Additional material studied. 1 female ( BPBM): FIJI: Viti Levu , Vuda Prov., 1.5 km SW Vaturu Dam, 550m, 14.VII.–26.VII.2004, Malaise trap: M01, E.I. Schlinger, A. Namaqa, -17.744, 177.676, FBA_221466 ; 1 female ( BPBM): same data as above but inventory number FBA_221472 ; 1 female ( BPBM): FIJI: Vanua Levu , Macuata Prov., 0.6km S. Rokosalase Village, 150m, 26.III.–9.IV.2004. Malaise Trap: M04, -16.533, 179.018, E.I. Schlinger. M. Tokotaa, FBA201056 ; 1 female ( BPBM): same data as above but inventory number FBA201057 ; 1 male ( 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_221572 ; 1 female ( BPBM): FIJI: Viti Levu , Naitasiri Prov., 2km E Navai, old trail to Mt. Tomaniivi, -17.521, 178, 700m, 24.XI.–9.XII.2003, Malaise: M03, E. I. Schlinger. M. Tokotaa. FBA204475 ; 3 females ( BPBM): same data as above but inventory numbers FBA204477, FBA204478, FBA204479 ; 1 male ( BPBM): FIJI: Viti Levu , Naitasiri Prov., 3.2 km E Navai Village, Veilaselase track, 1020m, 20.XII.2003 – 7.I.2004, Malaise trap: M01, E. Namatalau, -17.624, 178.009, FBA_216857 ; 5 females ( BPBM): same data as above but inventory numbers FBA201818, FBA201815, FBA201816, FBA201819, FBA_ 216858 .

Diagnosis. Contrasting coloration of dorsum with brown elytra and yellowish head and pronotum allow us easy identification of fully pigmented specimens. Uniformly brown, not fully pigmented specimens, can be identified on the basis of male genital characters: tegmen with very wide, subtriangular parameres.

Redescription. Lectotype, female. Body oval, convex, covered with brown setae, which are easily broken and missing on greater part of dorsum. Head, pronotum and scutellar shield yellowish, elytra brown with yellowish suture and humeral region. Antennomeres 1–3 yellow, remaining dark brown, legs brownish.

Head of moderate size, convex dorsally, shiny, covered with sparse and subtle punctures, separated by ca. 1.5–2.0 diameters. Eyes big, moderately protuberant; head 1.6× wider than interocular space. Antennae filiform, reaching basal 1/3 of elytra. Pronotum slightly convex, covered with sparse punctures, punctures separated by ca. 0.5–1.5 diameter, antero-lateral angles slightly projecting anteriorly, obtuse; lateral margins subtly rounded; postero-lateral angles almost right-angled; base of pronotum bisinuate, margination along basal margin well developed. Scutellar shield covered with shallow punctures, equilaterally triangular. Angle between pronotum and elytra not marked in dorsal outline. Elytra broadly oval, without traces of longitudinal ridges, widest in the middle, punctation stronger than on pronotum, distance between punctures ca. 1.0 diameter; humeri well marked. Hind tibial spurs well developed, dorsal spur curved, ca. 0.7× length of tarsomere 1, ventral spur slightly curved, slightly longer than 0.3× length of longer spur.

Ovipositor long (L 2.25 mm); prehensor formed by a folded lamina (L 0.42 mm, W 0.26 mm) surrounding bursa copulatrix; bursal sclerite absent, group of spines present in proximity of opening of accessory gland ( Fig. 7B , arrow).

Male. Sternite VIII (L 0.10 mm, W 0.27 mm) transversely U-shaped. Sternite IX (L 0.28 mm, W 0.24 mm) V-shaped, with setae on apical margin. Tergite VIII (L 0.52 mm, W 0.48 mm) with transversely trapezoidal apical plate, apical margin covered with row of setae, apodemes a bit longer than apical plate; tergite IX (L 0.37 mm, W 0.33 mm) with short and strongly transverse apical plate, apodemes ca. 1.5× longer than apical plate. Aedeagus asymmetrical. Tegmen (L 0.67 mm, W 0.30 mm) large, Y-shaped, with wide, subtriangular parameres, apices rounded ( Fig. 6C ). Penis (L 0.60 mm, W 0.12 mm) with narrow and elongate pala, apical processes short, hooked and pointed on apices ( Fig. 6D ).

Variability. TL is highly variable, both in male & females, and ranges from 2.2 mm to 3.3 mm. Coloration is brownish in not fully pigmented adults. Prehensor is quite variable in the studied specimens ( Figs 7B, 7E ).

Measurements and ratios. Males (n=2): TL 2.20–3.15 mm (2.68 mm), EL 1.65–2.80 mm (2.23 mm), PL 0.40– 0.55 mm (0.48 mm), EW 1.65–2.30 mm (1.98 mm), PW 1.10–1.55 mm (1.33 mm), TL/EW 1.33–1.37 (1.35), PW/ PL 2.75–2.82 (2.78), EL/EW 1.00–1.22 (1.11), EL/PL 4.13–5.09 (4.61), EW/PW 1.48–1.50 (1.49); females (n=8): TL 2.50–3.30 mm (2.88 mm), EL 2.15–2.85 mm (2.52 mm), PL 0.45–0.57 mm (0.49 mm), EW 1.95–2.30 mm (2.14 mm), PW 1.10–1.60 mm (1.40 mm), TL/EW 1.19–1.44 (1.33), PW/PL 2.20–3.33 (2.51), EL/EW 1.02–1.25 (1.15), EL/PL 4.30–6.11 (4.70), EW/PW 1.44–1.77 (1.64).

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

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 6. Scirtes spp., tegmen (A, C, E, F, J), penis, dorsal view (B, D, G–I, K). A–B) S. devoensis sp. nov.; C–D) S. hume- ralis Pic; E–I) S. tokotaai sp. nov.; J–K) S. veitchi Champion. Scale bar = 0.50 mm.

FIGURE 7. Scirtes humeralis Pic, female (A, C—genital tract and terminalia; B, D, E—close-up of prehensor; an arrow indi- cates a group of setae in the entrance to accessory gland). A–B) specimen from Viti Levu, BPBM; C–E) lectotype. Scale bars = 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.