Dichomeris arquata, Li, Houhun, Zhen, Hui & Mey, Wolfram, 2013

Li, Houhun, Zhen, Hui & Mey, Wolfram, 2013, Notes on Dichomeris Hübner, 1818 from Southern Africa and Kenya, with description of seven new species (Lepidoptera, Gelechiidae, Dichomeridinae), Zootaxa 3608 (7), pp. 561-574 : 562

Dichomeris arquata sp. nov.

( Figs 1 , 13 )

Type material. MALAWI: Holotype 3, Nyika Plateau, W of Chelinda Camp, LF rain forest, 2100 m, 14. x.1996, leg. [W.] Mey & [M.] Nuβ, genitalia slide no. ZH09101 (MfN). Paratype: 1 3, Malawi, Nyika Plateau, W of Chelinda Camp, LF rain forest, 2200 m, 12.x.1996, leg. [W.] Mey & [M.] Nuβ (MfN).

Diagnosis. This new species can be separated from other species known from Africa by the saccal region curved semicircularly, the paired sicae arising from the posterolateral side of the saccal region and remote from each other.

Description. Adult ( Fig. 1 ): Wing expanse 14.0–15.0 mm. Head greyish brown. Ocellus absent. Labial palpus with second segment about four times length of diameter of eye, bearing long triangular scale tuft on dorsal surface, third segment short, about 2/5 length of second; first and second segments dark brown on outer surface, greyish brown on inner surface, dorsal scale tuft dirty white apically; third segment yellow, mixed with greyish brown on ventral surface. Antenna with scape dark brown on dorsal surface, greyish brown on ventral surface; flagellum alternately brown and dark brown on dorsal surface, grey and ciliate on ventral surface. Thorax and tegula dark brown; mesothorax without hair pencil arising from anepisternum. Forewing with distal third slightly narrowed to blunt apex, termen obliquely straight; ground colour dark brown, apically diffused with black scales; costal margin with greyish yellow spot at distal 1/4; fringe dark brown. Hindwing and fringe grey, fringe greyish white basally. Fore and mid legs greyish brown on outer surface, yellowish white on inner surface; hind leg greyish brown on outer surface, greyish white on inner surface.

Male genitalia ( Fig. 13 ): Uncus nearly oblong, anterior margin concave in a triangle. Gnathos strongly curved near basal 1/3; culcitula short coniform. Valva slightly shorter than tegumen-uncus complex, basal 1/3 narrow, parallel-sided, distal 2/3 nearly oval; ventral free lobe clubbed, about 1/2 length of valva, with sparse setae on distal 1/3. Vinculum shorter than tegumen-uncus complex; lateral lobe absent. Saccal region broad, curved in a semicircular arch; sicae arising from inner side of saccal region posterolaterally, remote from each other, clubbed, slightly sharp apically. Setose patch between tegumen and vinculum more or less oval. Phallus broadened gradually from base to apex, with two sclerotized lobes arising from zone: one lobe from dorsal surface, slender, sharp apically, slightly shorter than phallus; another lobe from right side, nearly triangular, beaked apically, about 1/2 length of dorsal lobe, with a small triangular process at inner side near base; cornutus arising from near distal 1/ 4 on ventral surface, stout, acuate at apex.

Female unknown.

Distribution. Malawi.

Etymology. The specific name is derived from the Latin word arquatus (= arched), referring to the saccal region curved in a semicircular arch.

Figures

FIGURES 1 – 6. Adults of Dichomeris spp. 1. D. arquata sp. nov., holotype 3; 2. D. brevicornuta sp. nov., holotype 3; 3. D. dentata sp. nov., holotype 3; 4. D. ligulacea sp. nov., holotype 3; 5. D. paulidigitata sp. nov., holotype 3; 6. D. tenextrema sp. nov., holotype 3.

FIGURES 13 – 18. Male genitalia of Dichomeris spp. 13. D. arquata sp. nov., holotype, genitalia slide no. ZH 09101; 14. D. brevicornuta sp. nov., holotype, genitalia slide no. ZH 09091; 15. D. dentata sp. nov., holotype, genitalia slide no. ZH 09093; 16. D. ligulacea sp. nov., holotype, genitalia slide no. ZH 09095; 17. D. paulidigitata sp. nov., holotype, genitalia slide no. ZH 09113; 18. D. tenextrema sp. nov., holotype, genitalia slide no. ZH 09115.