The larvae of Stigmella basiguttella produce leaf mines on Oak. This is a long sinuous gallery, widening gradually and filled with green frass, which becomes brown later in the year. The adult moth has a dark head, bronzy brown forewing with green tint and pale yellowish spot at base. Wingspan 4.5 to 6 mm. Adult moths are best confirmed microscopically.

Adult Leafmine

Wherever Oak, the larval foodplant is present.

Adult: In two generations May-Jun. Jul-Aug. Leaf mine: June to Oct.

The larval foodplant is Oak.

Widespread and fairly frequent, particularly in south eastern England. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as common.

Increasingly well recorded in Leicestershire and Rutland in recent years, particularly from the leafmines on Oak

http://www.leafmines.co.uk/html/Lepidoptera/S.basiguttella.htm

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/monotrysia/nepticuloidea/nepticulidae/stigmella/stigmella-basiguttella/