I live in southwestern Wisconsin.
On our 151 acres last year we had mulberrys all over, good for pies and 
making die stuff out of.  Good for smoking meat too.
This spring I thought they a little slow......  they are ALL dead? A few 
hundred of them, just gone.  No signs of leaf drop or any out of the 
ordinary behavior last fall.  Just dead now......

Any ideas?  Nematodes, root knot...... We've looked at all the suspects 
that Duck Duck Go comes up with.   I have a note off the the Forest 
Products Lab.....just up the road a bit.  No reply yet.

God bless,
Mike Rock