Gracillariinae 26 species. Wingspan 7-14mm. Small moths which characteristically rest with the anterior part of their bodies raised at an angle from the surface displaying ornamented front and middle legs. Their larvae at first mining and sap feeding in the epidermis of a leaf, then moulting, changing their mouthparts and feeding in full thickness mines, or in spun folded or conically rolled leaves. Most pupate in a silken cocoon or under a silken membrane under a leaf. The imagines of some species hibernate in conifers, ivy, etc.
Lithocolletinae 47 species. Wingspan 6-10mm. Small brightly coloured moths very similar in appearance with a distinctive pattern of white edged dark marks on a white, gold, orange or brown background. Their larvae initially have a sap feeding phase but then remain in the mine, lining it with silk which contracts and forms an inflated chamber in which they feed on the leaf tissue. They cannot leave the mine and pupate there, in the autumn generation falling to the ground within the leaf and emerging in the spring. Many can be identified from the foodplant, whether the mine is on the upper or lower surface of the leaf, and from the structure of the mine or cocoon. This subfamily includes the invasive Horse Chestnut leaf miner.
Phyllocnistinae 2 species. Wingspan 6-7mm. Very small moths whose larvae are sap feeders mining under the epidermis of leaves and stems and pupating in a cocoon under a turned over leaf edge.