weeping willow tree

I have a weeping willow tree aprox. 30 ft. tall and was doing vey well. last year it started to die back at the branches somewhat. All I did was prune the branches back.
This year I noticed a series of tiny holes going around the trunk and the tree is severly dieing back at the branches. can someone suggest what might cause this and what would be a remidy
thanks
bob

 

there is a typical dieback of willows locally, blackening of tips and new growth at the early stage then healthy regrowth after. the series of holes, could it be a woodpecker of some sort?

 

Thanks for the info.

 

Here is a thread which shows a picture and discusses the damage caused by sapsuckers in detail.

Raakel

 

Thank you, I'll try tanglefoot and see what happens
Bob