Phyllonorycter brachylaenae is a moth of the family Gracillariidae. It is known from South Africa.Global Taxonomic Database of Gracillariidae (Lepidoptera) The habitat consists of understory vegetation in secondary forests.
The length of the forewings is 3.06–3.33 mm. Adults are on wing from early March to mid-May and from late June to late October.Systematics, revisionary taxonomy, and biodiversity of Afrotropical Lithocolletinae (Lepidoptera: Gracillariidae)
The larvae feed on Brachylaena discolor and Brachylaena rotundata. They mine the leaves of their host plant. References