Gnathothlibus fijiensis, Lachlan, 2009

Lachlan, Robert B., 2009, Two New Species of Gnathothlibus Wallengren from Fiji and Samoa and a New Species of Theretra Hübner from New Guinea (Lepidoptera: Sphingidae), Records of the Australian Museum 61 (1), pp. 73-87 : 74

Gnathothlibus fijiensis n.sp.

Figs 1–4 , 14

Type material. HOLOTYPE?, FIJI: 3 km E of Komave, south coast of Viti Levu , 18°13'36.2"S 177°46'25.7"E, 16 April 2008, R. B. Lachlan, AM K266025 . PARATYPES 9 ??, 2 !!: 7 ?? with same data as holotype but 2 dated 8 April 2008 in RBLC , 1 ( AM K266026 ) dated 9 April 2008, 1 dated 13 April 2008, 1 dated 15 April 2008, 1 dated 16 April 2008 and 1 dated 7 December 2008 in RBLC . 2 ?? H. Phillips, Vunidawa, Fiji, 18.8.1932, Lautoka , Fiji, 19.6.27, H. Phillips in AM . 2 !! with same data as holotype, 1 dated 16 April 2008 in RBLC , 1 ( AM K266027 ) dated 6 December 2008 in AM .

Diagnosis. In male, olive green ground colour on forewings. Ventral surface of head, thorax and abdomen olive green. Mauve lateral stripe on the outer edges of the tegulae above both wings. A prominent dark, mostly straight, post median line runs from costa, where it is curved slightly distally, to inner margin. Female forewings brown with prominent dark, mostly straight, post median line as in male. Genitalia with uncus, in lateral view, long, slender, parallel-sided for nearly the whole of its length, slightly arched with the distal margin slightly convex and slightly angled backwards dorsally with a small dorsal crest. The distal margin has a small, dark ventral tooth.

Description. Male. (Figs 1,2,14). Antennae creamy-brown above, dark brown below; palpi olive green above, contrasting off white below; dorsal surface of head and prothorax darker olive green, remainder of thorax and abdomen uniform olive green; small dark median spot with posterolateral orange-brown on prothorax; thin lateral creamyolive stripe from base of antennae to forewing, continuing as mauve on the outer edges of the tegulae above both wings. Thorax ventrally with creamy, light brown patch immediately posterior to palpi, remainder of median band creamy-olive along thorax dissipating as it reaches upper abdominal segments. Abdominal segments laterally each with orange-brown posterior margin contrasting with olive green ground colour, abdomen with four small lateral black spots surrounded clearly by white. Fore-tibae covered in long creamy-olive hair scales; proximal three segments of foretarsi covered in shorter creamy-olive hair scales, shortest on distal segment, longest on proximal segment.

Forewing upperside as in Fig. 1 . Forewing length 38–41 mm, mean 39.6 mm (n = 7). Ground colour olive green (brighter in fresh specimens) with darker markings; some specimens exhibit less green; small black stigma with light coloured centre at end of discal cell; irregular, oblique, submarginal dark line from costa to vein M 3, wider between veins M 2 and M 3; a prominent dark, mostly straight, post median line runs from costa, where it is curved slightly distally, to inner margin; a short, irregular, subbasal band edged on each side by dark lines and curved distally, runs from costa to the dark basal patch below vein 1A+2A. Forewing underside as in Fig. 2 . Ground colour burnt orange, lighter basad with two short, antemedian orange-brown streaks near costa and one near base; distally darker brown with usually two dark, irregular, parallel post median lines from costa to vein M 1; these lines may be vestigial or well developed in some specimens.

Hindwing upperside as in Fig. 1 ; ground colour orange; a slightly variable dark brown terminal band from apex to tornus at least 2 mm wide, slightly thinner at apex; inner margin of band slightly irregular with brown scales along veins M 1 to M 3 for about 2 mm. Hindwing underside ( Fig. 2 ) with ground colour light orange-brown, heavily speckled with dark brown; marginal area darker from apex to tornus; dark, mostly straight, median line, thickest at costa, curving proximad from costa to vein M 1 and usually reaching vein CuA 1 but does not touch distal edge of cell; a much less prominent, small, parallel dark post median line to vein R s, vestigial in most specimens.

Male genitalia ( Fig. 14 ). Uncus in lateral view, long, slender, parallel-sided for nearly the whole of its length, slightly arched, distal margin slightly convex and slightly angled backwards dorsally with small rounded dorsal crest, distal margin with, dark ventral tooth; gnathos in lateral view thin, straight, distal margin tapering to a small, slightly upturned point; in dorsal view gnathos is wide basally with slightly curved sides tapering evenly to a point; valvae dorsal margin straight proximally then slightly convex, then distally straight, distal margin rounded, ventral margin gently convex; sacculus process well developed; harpe robust, distal end smooth surfaced and spine-like, upturned; aedeagus in lateral view with distal end tapered to a bluntly rounded apex with backward directed dorsal fishhook-like barb, ventrally with a small, similar barb, a little proximad of dorsal barb.

Female ( Figs 3–4 ). Forewing length 40–44 mm. Head and tegulae dark brown. Median area of thorax and abdomen above medium brown. Thin lateral cream stripe from base of antenna to posterior edge of tegula above hindwing, not mauve as in male. Thorax below uniform orange-brown; abdomen ventrally pale pinkish-brown with four well-developed lateral white spots with small black centres. Fore-tibae covered in short hair scales, light brown on anterior edge and cream on posterior edge; fore-tarsi without hair scales.

Forewing upperside as in Fig. 3 ; ground colour and pattern in shades of darkish-brown, lacking green colour of male; small dark brown stigma with light centre at end of discal cell; a prominent dark brown, almost straight, post median line runs from costa and curved slightly distally to inner margin as in male. Forewing underside as in Fig. 4 ; ground colour medium brown, distinctly speckled with dark brown distally; a dark brown irregular, submarginal line runs from apex to tornus; two variable dark brown parallel post median lines from costa often reaching vein CuA 2.

Hindwing upperside ( Fig. 3 ) orange as in male, but dark brown terminal band broader, with inner margin generally quite straight and suffused with orange scales; hindwing underside ( Fig. 4 ) ground colour same as forewing but more heavily speckled with dark brown; yellowish streak along proximal side of vein 1A+2A.

Etymology. The specific name fijiensis is derived from the Pacific island nation of Fiji, the only known locality for the species.

Distribution. At present G. fijiensis is known only from the main island of Viti Levu, Fiji.

Figures

Fig. 1. Gnathothlibus fijiensis n.sp. holotype male, upperside.

Fig. 2. Gnathothlibus fijiensis n.sp. holotype male, underside.

Fig. 3. Gnathothlibus fijiensis n.sp. paratype female, upperside.

Fig. 4. Gnathothlibus fijiensis n.sp. paratype female, underside.

Fig. 14. Gnathothlibus fijiensis n.sp.