Phyllonorycter pygmaea
Phyllonorycter pygmaea is a moth of the family Gracillariidae. It is known from Japan, Korea and the Russian Far East.
The wingspan is 5-5.5 mm.
The larvae feed on Castanea crenata, Quercus acutissima, Quercus crispula, Quercus mongolica and Quercus serrata. They mine the leaves of their host plant.