Hymenoptera: Cynipidae - gall wasp Andricus quadrilineatus Agamic generation - photographs on Quercus, Oak Hosts: Agamic and sexual generations on Quercus petraea, pubescens, robur. Both generations are dependent on anthers and occur in early spring. Agamic - unilocular catkin gall, 3-4mm long with several longitudinal ridges. Very occasionally galls can occur on young leaves Sexual - elliptic, unilocular catkin gall, 2mm. The gall is smooth with a bunch of long white hairs at the top

Andricus quadrilineatus
Broadstone, Dorset. September 2017