Axial Borer

 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

 

From what I've read on the Canadian Forestry site, some parasites gain entry
thru cracks in the tree-bark, damaged wood or sap-holes. At least with
pines, leaking sap is a powerful attractant.

Out here in the country where the drought is biting deep, any sick or
thirsty trees are more susceptible, apparently. The sheer number of
different parasites makes it difficult to gain the satisfaction of knowing
which one it is.

Jason

 

Thanks Jason,

I agree that the water stress is probably making plants more susceptible.

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.

 

But with

the plant

borehole has

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?

 

Perhaps.  But in each of my cases, as I lop further down, I get to a point
where there is no longer a centre hole.  So, mine start above ground level.

I have spoken to a couple of nurserymen and they say that they started
seeing this in the last year as the drought worsened.  50mm rain today.
Whoopee!