Eridachtha nairobiensis Park 2024, sp. nov.

4. Eridachtha nairobiensis Park, sp. nov.

LSID: urn:lsid:zoobank.org:act: 0D173E41-E0B5-4DBA-B8F7-797DC0B359D8 (Figs 9, 10)

Type specimens. Holotype male: Kenya, Nairobi, Oluloa Forest NMK-IPR Compound 01˚21'49''S 36˚42'47''E, 1,822 m, MV Light, 15 viii 1999, leg. D.J.L. Agassiz, gen. slide no. CIS-7593, in NHMUK. Paratypes: 1♀, same data as holotype, gen. slide no. CIS-7623.

Diagnosis. This new species is the smallest species of the genus. The male genitalia are somewhat similar to those of E. kilimanjaroensis Park, sp. nov., but can be distinguished by the gnathos basal plate triangularly produced apically (Fig. 10 A-①) (rounded in E. kilimanjaroensis) and the cucullus slightly narrower toward apex, with a sharply angulate process at lower corner.

Description. Male and female (Figs 9A–D). Wingspan 11.0– 11.5 mm.

Head: vertex with appressed orange-white scales, with concolourous erect scales laterally. Antenna about 1.2 times longer than forewing; scape elongated, nearly parallel-sided, orange-white throughout, without annulation. Second segment of labial palpus thickened, with rough scales, more ventrally; yellowish-white speckled with brownish scales on outer surface; 3 rd segment slightly longer than 2 nd segment.

Thorax: tegula and thorax orange-white. Hind tibia with strong setae-like scales above and below. Forewing densely covered with yellowish-brown scales evenly, with weakly developed blackish discal spots at middle and at end of discal cell; costa gently arched before middle; apex sharply produced; termen remarkably oblique, slightly concave medially; fringe with white basal line and broad dark-brown median band, concolourous with ground colour. Hindwing ground colour greyish; apex sharply produced; fringe with white basal line.

Abdomen: no spinous zones on dorsal surface.

Male genitalia (Figs 10A, B): uncus basal lobes ovate laterally. Gnathos basal plate quadrate triangularly produced apically; median process strongly bent pre-apically. Costal bar narrow and slightly angulate medially.Valva broad basally; cucullus elongated; costa slightly convex beyond half, with dense setae along ventral margin, slightly narrowed apically; sacculus broadly developed, heavily sclerotized. Juxta shield-shaped, with narrow, membranous latero-caudal processes; emarginated medially; anterior margin more or less triangularly produced. Vinculum broad, U-shaped, sclerotized along lateral margin, broadened apically, with rounded saccal zone. Aedeagus as long as valva, narrowly produced apically, with a pair of small triangular processes on dorsal margin; cornutus forming a sac.

Female genitalia (Fig. 10D): apophyses anteriores about 2/3 the length of apophyses posteriores. Antrum cup-shaped, weakly sclerotized, about twice wider than long. Ductus bursae narrowed in distal 1/4, then widely broadened in anterior 3/4 (with several irregular sclerotized plates medially), not well defined with corpus bursae. Corpus bursae ovate; signum plate with strongly sclerotized, vertical ridge centrally, about 1/2 the length of corpus bursae.

Distribution. Kenya (Nairobi).

Etymology. The species name is derived from the type locality.