Cosmopterix Hübner, 
All of the Cosmopterix species occurring in Hong Kong are only provisionally identified by comparison of external morphology to material at The Natural History Museum (BMNH), London. They require genitalic dissection to confirm their identities. There are at least three species of Cosmopterix with this type of wing patterning in Hong Kong. The smallest species, with a wingspan (twice the forewing-tip to thorax measurement) of about 8 mm, is illustrated. The larger species (w/s = 12mm) are less abundant at light traps.
Cosmopterix sp. nr. basilisca Meyrick, 1909
Global distribution: unknown.
H.K. distribution: widespread.
H.K. status: common in woodland and tall shrubland.
H.K. phenology: multivoltine, a few records between late January and early April, then common between late July and mid-November
Cosmopterix species near basilisca
Cosmopterix hamifera Meyrick, 1909
Global distribution: South Africa, India, Sri Lanka (coll. BMNH).
H.K distribution: restricted (Kwun Yum Shan, Central New Territories; Chatham Path, Hong Kong Island).
H.K. Status: rare in woodland.
H.K. phenology: single records in May, June and August.
Notes: distinguished from C. aculeata and C. sp. nr. basilisca by the extension of the f/w orange post-medial area beyond the post-medial fascia to the termen.
Cosmopterix aculeata Meyrick, 1909
Global distribution: India (Assam), China, Australia (coll. BMNH).
H.K. Distribution: widespread.
H.K. Status: frequent in woodland.
H.K. phenology: multivoltine, recorded from March to November in an undetermined number of generations.
Notes: similar to Cosmopterix sp. nr. basilisca, but larger, with the forewing post-medial area lemon yellow rather than orange and with a wing span of around 12 mm rather than 7 to 8 mm. The listing of Cosmopterix flavofasciata Woll. by Lee & Winney (1982) is referable to this species. Material identified as Cosmopterix attenuatella (Walker, 1864) from Taiwan and Jamaica (!) (Heppner & Inoue, 1992) exists at the Tai Lung Experimental Station (Agriculture, Fisheries & Conservation Department, H.K. Govt.), which appears identical to C. aculeata. Clearly, there is a need to establish which of these species is actually the one present in Hong Kong!