By Bigmoben
United Kingdom 
We have a small willow tree in our front garden, a Kilmarnock tree I think. Last year it was infested by caterpillars which ate most of the leaves. I sprayed the tree which got rid of the caterpillars and pruned the tree right back.
This year it has grown very well with lots of new shoots and leaves. I was looking at it today and noticed yellow deposits on the underside of some leaves and lumps on others. I have attached a few photos showing this.
Can you help by advising what this is and how it can be treated.
26 Jun, 2017
Willow Mite Galls? Don't think there is anything you can spray for them though, unless someone else has any success with spray.
26 Jun, 2017