Perittia gnoma, Sruoga, Virginijus & Prins, Jurate De, 2009

Sruoga, Virginijus & Prins, Jurate De, 2009, The Elachistinae (Lepidoptera: Elachistidae) of Kenya with descriptions of eight new species, Zootaxa 2172, pp. 1-31 : 15-17

Perittia gnoma , new species

( Figs. 1 , 15 , 32 , 37–40 )

Type material. Holotype: 3, KENYA, Arabuko Sokoke Forest, 20 km W Gede, 90 m, 03°25’S 039°53’E, 31.iii.2004, leg. J. De Prins, specimen ID RMCA ENT 0 0 0 0 0 5176, gen. prep. MRAC / KMMA 0 0 473 ( RMCA).

Paratypes: 13, same locality as holotype, 25.iii.2004, leg. J. & W. De Prins, specimen ID RMCA ENT 0 0 0 0 0 5177, gen. prep. MRAC / KMMA 0 0 474 ( RMCA). 13, Arabuko Sokoke Forest, 03°25’S 039°53’E, 40 m, 21.iv.2002, leg. J. De Prins, specimen ID RMCA ENT 0 0 0 0 0 5147, gen. prep. MRAC / KMMA 0 0 475 ( RMCA).

Diagnosis. In wing pattern, the species is indistinguishable from P. spatulata , known from the same locality. The main differences in male genitalia between P. gnoma and P. spatulata are the following: (1) apex of cucullus in P. gnoma with one small upcurved tooth ( Fig. 39 ), in P. spatulata with several minute teeth ( Fig. 46 ); (2) inner surface of cucullus in P. spatulata without tapering process, in P. gnoma with tapering process ( Figs. 37, 39 ); (3) sacculus meeting cucullus at sharp angle (about 50–80º) in P. gnoma versus blunt angle (about 110–145º) in E. spatulata ; (4) ventral shield of juxta about 1/2 length of phallus in P. gnoma , about 3/ 4 in P. spatulata ; (5) apex of phallus pointed in P. gnoma ( Figs. 37, 40 ), in P. spatulata with broad, strongly sclerotized process ( Figs. 45, 47 ).

Male ( Fig. 32 ). Forewing length 2.3–2.6 mm; wingspan 5.2–5.9 mm (n=2). Head: Vertex and neck tuft pale ochre, some scales with brownish-black tips; background layer of frons with some metallic lustre; labial palpus very short and straight, yellowish white above, fuscous below; scape broader than flagellum, covered with yellowish-white scales with brownish-black tips; flagellum rather broad, unicolourous, brownish grey. Ground colour of thorax, tegula, and forewing pale ochre to ochre, mottled due to brownish-black tips of scales. Denser brownish-black scales forming two irregular patches: one in basal part of wing; other extending obliquely at 2/5 of costa towards tornus of wing. Brownish-black scales forming two small spots: one at 2/5 from wing base and other at 3/5. Fringe scales brownish grey with irregularly scattered brownish black-tipped scales. Hindwing blackish brown, its fringe brownish grey.

Female. Unknown.

Male genitalia ( Figs. 37–40 ). Uncus short, posterior margin weakly sclerotized. Basal arms of gnathos rather long; spinose knob of gnathos wider than long, tapered towards apex. Valva short and broad; costa slightly convex; sacculus convex, distally strongly concave, forming sharp angle when meeting cucullus; cucullus narrow and long, about 4 times longer than broad, apex with small upcurved tooth, inner surface with long, slender and acute process ( Fig. 39 ). Ventral shield of juxta lightly sclerotized, elliptical with broadlyrounded proximal end and weakly-concave distal end, about 1/2 length of phallus; juxta lobes short and narrow. Digitate processes not developed. Vinculum U-shaped, without saccus. Phallus short, about 4 times longer than broad, ventral wall with long and narrow incision in apical part, dorsal wall tapering, apex pointed, weakly sclerotized; vesica with few tiny spines and two clusters of large cornuti (2–3 and 6–7) slightly varying in size.

Biology. Unknown.

Flight period. Based upon the two specimens available, adults fly in late March and April.

Distribution. So far this species is known only from the Arabuko Sokoke Forest Reserve in the Coastal Province of Kenya ( Figs. 1 , 15 ).

Etymology. The species name is derived from the Latin gnomus (dwarf), referring to the small body size of this species.

Remarks. This species, along with P. spatulata and P. tantilla , differs from all other known species of the Elachistinae by the direction of the spines on the apical knob of the gnathos. The tips of the gnathos spines are directed anteriorly rather than posteriorly in all other species. In the male genitalia the juxta is fused with the phallus, therefore during preparation, if the phallus is removed, the juxta lobes can be separated from the juxta along with the phallus ( Fig. 40 ).

Figures

FIGURE 15. Collecting localities of Elachistinae species in Kenya: 1, Arabuko Sokoke Forest National Park; 2, Aberdares National Park; 3, Hell's Gate National Park; 4, Kakamega Forest National Reserve.

FIGURES 1 – 4. Collecting localities in Kenya. 1, Arabuko Sokoke Forest National Park; 2, Aberdares National Park; 3, Hell’s Gate National Park; 4, Kakamega Forest National Reserve.

FIGURES 32 – 36. Adults of Perittia species. 32, P. gnoma sp. n., male, holotype. Specimen ID: 000005176; 33, P. falciferella sp. n., female, paratype. Specimen ID: 000005180; 34, P. spatulata sp. n., male, holotype. Specimen ID: 000005159; 35, P. spatulata sp. n., female, paratype. Specimen ID: 000005172; 36, P. tantilla sp. n., male, holotype. Specimen ID: RMCA ENT 0 0 0 0 0 5148. Scale bar 1 mm.

FIGURES 37 – 40. Perittia gnoma sp. n., male genitalia. 37, valvae, juxta and phallus; 38, uncus, tegumen, gnathos and vinculum. Holotype, gen. prep. MRAC / KMMA 0 0 473, specimen ID: RMCA ENT 0 0 0 0 0 5176. Scale bar 0.1 mm. 39, valva; 40, apical part of phallus and juxta lobes (a, juxta lobe). Paratype, gen. prep. MRAC / KMMA 0 0 474, specimen ID: RMCA ENT 0 0 0 0 0 5177.

FIGURES 44 – 47. Perittia spatulata sp. n., male genitalia. 44, general view (juxta and phallus removed); 45, juxta and phallus, lateral view. Paratype, gen. prep. MRAC / KMMA 0 0 464, specimen ID: RMCA ENT 0 0 0 0 0 5160. Scale bar 0.1 mm. 46, lateral part of genitalia; 47, apical part of phallus and juxta lobes (a, spatula shaped process of phallus; b, juxta lobe). Holotype, gen. prep. MRAC / KMMA 0 0 463, specimen ID: RMCA ENT 0 0 0 0 0 5159.