My eureka lemon tree recently quickly died. When I cut it down I found that
an axial borer had drilled out the centre of the wood. The borer had got
right down into the stump.
I quickly disposed of the cuttings but now it is in three Murraya bushes.

I have not seen the borer. The wood shows no entry point that I can find.
There is no saw dust.

Regards
Doug