Hymenoptera: Tenthredinidae - sawfly Euura atra Gall on Salix alba var. vitellina, Golden Willow / Yellow Basket Willow. Adult ex gall Hosts: Salix alba, S. x fragilis. Very occasionally on S. viminalis Causes a slight swelling on young twigs (to 1.5cm long), the bark remaining smooth. The single greenish larva pupates in the gall.

Euura atra
Poole Park and Studland Heath, Dorset. March 2018