Diagnosis: This species is closely similar to N. ranomafanaensis, but can be distinguished by the reduced or absent apical processes of the aedeagal shaft and the absence of forewing crossvein r-m 1.
Description: Length of male, 4.6–4.8 mm; female, 5 mm.
External characters and coloration as in N. ranomafanaensis.
Male genitalia closely resembling those of N. ranomafanaensis, but aedeagal shaft with processes absent or reduced to tiny lobes.
Material examined: Holotype male, MADAGASCAR: Province d’Antananarivo, 3 km 41° north-east of Andranomay, 11.5 km, 1300 m, 18°28′24″S, 47°57′36″E, 5.–13.xii.2000, Fisher, Griswold et al., BLF2375, CASENT5502778 (CAS). Paratypes: two males (CASENT5501890, CASENT5502683), one female (CASENT5501002), same data as holotype (CAS, INHS); one male, MADAGASCAR: Province d’Antsiranana, Parc National Montagne d’Ambre, 12.2 km 211° south-south-west of Joffreville, 1300 m, 21°35′47″S, 49°9′34″E, 2.–7.ii.2001, Fisher, Griswold et al., BLF2853 (INHS).
Etymology: The specific epithet is derived from the Latin affinis meaning similar, referring to similarity with N. ranomafanaensis.