Leaf of a blackberry, Rubus fruticosus, mined by the larva of the blackberry pygmy moth, Stigmella aurella. The picture shows the serpentine tunnel (white) which has been produced by the larva as it grows by eating the green tissue between the upper and lower epidermis of the leaf. The moth laid its egg towards the lower left corner of the picture, where the tunnel is at its narrowest. Stigmella aurella is a micro-moth of the family Nepticulidae. The adult insect has a wingspan of only 3-4mm. Mined leaves are easily found on blackberry leaves, including both wild brambles and cultivated plants grown for fruit, but the insect has no economic impact