Theretra tabubilensis, 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 : 85-86

Theretra tabubilensis n.sp.

Figs 10, 11 , 20

Type material. HOLOTYPE? , PAPUA NEW GUINEA. Tabubil , Western Province , 5 ° 15 'S 141°13'E. Alt. 650 m. 22 Sept. 1992, R.B. Lachlan AM K266034. PARATYPES 3 ?? same data as holotype except dated 28 Oct. 1992, 19 Nov. 1992, 29 Nov. 1992; 1? SE slopes of Mt Akrik (Ian), 15 km NW of Tabubil, W.P., 5°10'S 141°09'E, Alt. 1625 m, 14 Apr. 1994, R.B. Lachlan; 1? Kiunga , north Fly River , W.P. 6°08'S 141°17'E, 15 Nov. 1992, R.B. Lachlan; 1? 30 km E of Tari, S. H. P. 5°58'S 143°07'E, Alt. 2300 m, 3 Oct. 1992, R.B. Lachlan; 11 !! same data as holotype except dated 15 Mar. 1991, 5 Nov. 1991, 27 Mar. 1992, 11 Oct. 1992, 28 Oct. 1992, 8 Nov. 1992, 22 Mar. 1993, 4 Oct. 1993, 12 Nov. 1993, 5 Apr. 1994, 10 Jan. 2000; 1! Matkomrae (Matkomnai) Catholic Mission, 50 km NNW of Kiunga, W.P. 5°49'S 140°09'E, Alt. 60 m, 6 Nov. 1993, R.B. Lachlan, all specimens in RBLC; 2 !! Kiunga, north Fly River, W.P. 6°08'S 141°17'E, 15 Nov.

1992, R.B. Lachlan AM K266035 and RBLC.

Other material examined. 2 ??, 3 !!, same data as holotype except dated 29 Mar. 1992 (2), 3 Nov. 1992, 11 Nov. 1993 (2); 1? Se slopes of Mt Akrik (Ian), 15 km NW of Tabubil, W.P. 5°10'S 141°09'E, Alt. 1625 m, 26 Sept. 1993, R . B. Lachlan, all in BMNH .

Other material. 1! “ B.C. New Guinea, Mount Kebea , 6,000 ft., March-April 1903, A.E. Pratt ”, 1? “ B.C. New Guinea, Mount Kebea , 3,600 ft., July 1903, A.E. Pratt ”, 1? “ B. New Guinea, Mafalu, 6,000 ft., September 1903, A.E. Pratt ”, 1! “ N. Dutch New Guinea, Waigeu, Camp Nok, 2,500 ft., v.1938, L.E. Cheesman ” and 1! “ Dutch New Guinea, Central Arfak Mts. , Ninay Valley, 3500 ft., Nov ’08 to Jan. ’09”, all in BMNH .

Diagnosis. Forewing with single, almost straight, olivebrown oblique line from apex to near centre of inner margin. Small, diffuse, dark patch distad of stigma near costa, not reaching oblique line. Anal area of hindwing light creamybrown, remainder of wing dark brown with lighter creamybrown patch at distal end of vein CuA 2. Aedeagus, viewed laterally, with convex distal margin and a line of dense, short spines angled backwards from the dorsal surface of distal margin to lateral surface. Female almost identical to male, often slightly darker.

Description. Male. Fig. 10. Antennae creamy-pink above, ventrally light brown; palpi olive-brown above, suffused with cream below; upper surface of head and thorax uniform olive-brown, slightly lighter on dorsal surface of abdomen with lightly scattered suffusion of black scales; small dark spot on prothorax; thin lateral creamy-olive brown stripe above palpi to base of tegulae above hindwings. Thorax, laterally, with dense darker olive-brown pilosity from head to base of forewings, small patch of orange-brown pilosity near base of forewings; creamy-brown along length of abdomen with diffuse, dark, lateral patch extending distally from near base of hindwing about 10 mm along abdomen; ventral abdominal segments light creamy-brown suffused with black scales. Fore-tibae creamy-olive brown, fore-tarsi without long hair scales.

Forewing upperside as in Fig. 10. Forewing length 32.5–38.7 mm, mean 35.9 mm (n = 10). Ground colour in shades of lighter and darker olive-brown, slightly variable; very small dark olive-brown stigma at distal end of discal cell; single prominent, almost straight, olive-brown line from apex, where it curves slightly distally, to just distad of halfway point of inner margin; this line unbroken at apex in almost all specimens examined; costa dark olive-brown, proximal side of oblique line slightly lighter than distal side of oblique line; small, diffuse, darkish patch just distad of stigma; proximal half of forewing very lightly speckled with dark scales, distal half more heavily speckled; single, faint, irregular, darkish subbasal line from costa to vein 1A+2A; small, rounded darkish patch at base on posterior half of forewings, continuing as flattened light then darkish wedgelike marking along inner margin, its point almost touching the dark oblique line. Forewing underside with dark tan region basally extending past discal cell, medium tan on remainder of proximal half of wing, light tan on submarginal area from apex to tornus, whole underside, except dark basal region, clearly speckled with black scales.

Hindwing upperside as in Fig. 10. Ground colour darkish brown, small, pale, creamy-brown patch between veins CuA 2 and 1A+2A, then darkish brown streak to tornus; thin, pale, creamy-brown patch from tornus along inner margin to base. Hindwing underside with basal region pale tan, distal region darker as in distal region of forewing but with faint pinkish tinge, speckled, as in forewing, with a row of oblique, post median darkish dots from costa, where they curve distally, down to vein CuA 2.

Male genitalia. Fig. 20. Uncal lobe, in lateral view, gently arched, slender centrally with slightly enlarged distal region, ventral surface of distal margin with blunt, downward point; gnathos short, evenly curved upwards, dorsal surface slightly serrated at distal end; aedeagus, in lateral view, long, slender, parallel sided, distally enlarged with a line of dense, short spines angled from the dorsal surface to the lateral surface; distal margin with small blunt point at tip of dorsal surface, then angled backwards with small inward curve then clear convex bulge to ventral surface; harpe small, volcano-like with tiny serrations on concave dorsal surface.

Female. Fig. 11 . Forewing length 34.2–40.7 mm, mean 38.2 mm (n = 17). Overall appearance, upperside and underside, is identical to male but ground colour usually slightly darker.

Etymology. The specific name, tabubilensis , is derived from the mining town of Tabubil in the Western Province of Papua New Guinea, where most specimens were collected.

Distribution. At present most specimens have been recorded from the Tabubil area in the central far west of PNG near the border with Indonesia, 3 specimens have been recorded approximately 90 km to the south at Kiunga on the Fly River and 1 specimen from approximately 30 km east of Tari in the Southern Highlands Province, some 200 km ESE of Tabubil. Other specimens held in The Natural History Museum, London, include specimens from Waigeu Island, just off the northwest coast of New Guinea and the Arfak Mountains in the far northwest of Indonesian New Guinea. It appears to be primarily a mountain species.

Figures

Fig. 11. Theretra tabubilensis n.sp. paratype female, upperside.