Help…large shrub covered with white disease or fungus.

[Tetters]

Looking at your photos again, I'm also concerned that your shrub is surrounded by wood chippings. These insects will be quite happy in there too, so it would be a good plan to clear them from the contaminated area and chuck them on the bonfire as well.
Give the remaining stump (about an inch of stump, if that) a bucket of water, and wait for re growth.

 

[Straightbat]

Maybe I could treat the bark with one of the recommended treatments. But there was no sign of any infestation on the bark, and since the little beasties suck sap they're not going to get any joy on bark chippings.

 

[Logan]

I think flowering currants will survive cutting right down, it might take a while.

 

[Straightbat]

Yes, it has been severely cut back before and is 23 years old.

 

[Jan]

Spraying with methylated spirit kills those.

 

[Straightbat]

Any thoughts on this white stuff where the variegated wigeia has been cut down in the past? There is also some you can see lower down on the same branch/trunk.