Gracillariidae is an important family of leaf miners that includes several economic, horticultural or recently invasive pest species such as Cameraria ohridella. The family occurs in all terrestrial regions of the world except Antarctica.
Most larval Gracillariidae undergo hypermetamorphosis, meaning there is a major change within the larval stage. Early instars have a flattened head and body, modified mandibles, and lack functional spinnerets or legs; these feed on sap. Later instars are cylindrical with round heads, and have chewing mouthparts, legs and functional spinnerets; these feed on plant tissue. Some species additionally have a spinning instar that does not feed, and others have a non-feeding instar before this spinning instar.
Many host plants are known, generally dicotyledonous trees or shrubs.
Source: Wikipedia