Andricus curvator

Andricus curvator is a Cynipid gall wasp that causes galls to form in the leaves of Oak.

The sexual generation gall is more often recorded in oak leaves or occasionally in a twig; rarely in catkins.  In the leaf, it is roughly globular, about 8 mm across and often distorts the leaf and midrib; sometimes several galls coalesce. In a twig, it causes a swelling and usually a bend in the twig, with a spherical inner gall.

The asexual gall is in a bud, and is ovoid or pip shaped, smooth and greenish with a white ring behind the tip at first. 

The sexual galls of Andricus inflator are also in a twig, but with a long and narrow interior cavity; to record these two galls the gall needs to be opened.

Agamic gall Sexual gall Adult

Where Oak is present.

June and July.

Widespread and fairly frequent in Britain.

Status in Leicestershire and Rutland not known.