The larvae of Trioza remota cause galls to form on the leaves of English Oak and Sessile Oak. These take the form of a raised pimple on the upper surface of the leaf about 1 to 2 mm across, often several to a leaf. On the underside of the leaf there is a corresponding shallow depression which contains a flat, pale orange-yellow nymph.

Gall Adult

Where the host species of oak occur.

May to October.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.