"The Old Bloke" wrote in message

I have often dealt with borers that go in, leave a trail of dust.
But with
whatever these are, there is no visible sign till a major part of
the plant
dies. When I then start lopping off the dead branch, the axial
borehole has
usually got right down into the lower trunk. A single hole can be
4-6 ft
long.

I also recently had a lemon tree looking as sick as it was possible to
be without actually being dead. I finally got sick of trying to
cosset the rotten thing and pulled it out. It was young and small so
I could check it out well when I ripped it up and I found a hole right
at ground level which wasn't visible when in the ground. There was no
other borer hole anywhere to be seen. Could this have been an axial
borer?