Question
Hello Tom,
I have 2 weeping willows in my front yard in VA.  The leaves are turning yellow and coming off.  At a closer look, there are grey colored bugs the look like bumps on the branches.  LOTS.  What are these and can i get rid of them?

Answer
Hi Cassandra,
Thanx for your question.  I'm really not a Tree Expert.  We have a tree expert here on Allexperts, Jim Hyland.  If you will go to Home/Gardening, click on Trees and then Click on Trees again, you'll find Jim.

I looked for the bug but did not see what you may have been describing.  You may want to take a look at the UC-Davis site.
http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/willow.html

I hope this helps.
Tom