Stigmella monella is a moth of the Nepticulidae family. It is found in the Russian Far East, Japan (Hokkaido) and probably north-eastern China. There are probably at least two generations per year. The larvae feed on Acer mono and Acer crataegifolium. They mine the leaves of their host plant. The mine consists of a linear-blotch, starting as a thin and contorted gallery, gradually becoming broader towards two thirds of the length of the mine. Then it widens into a large blotch. The frass in first part of the mine is broken-linear, sometimes deposited as a minute mass within each leaf-areola. Later, the frass is neatly coiled and occupying almost the whole width of the mine. At the end, the frass is dispersed and found in a wide line occupying about half the width of the mine. In the blotch