Hymenoptera: Cynipidae - gall wasp Andricus seminationis Agamic generation - photographs on Quercus, Oak Hosts: Only agamic generation known, on Quercus petraea, pubescens, robur Usually several together in male catkins, very occasionally occurs on leaves (attached to margin). Galls are slender, 6-8mm with longitudinal ridges, stalk 5mm. Young gall is green with short, non-persistent hairs

Andricus seminationis
Broadstone, Dorset. September 2017