in my mandarin tree
have spent a lot of time and expense on this tree as the leaves
were yellow, and have taken all sorts of advice. However, two branches
of the tree went dead and we cut them off and found a hole right
through the branch as if something was eating it through the bark.
Can you advise as to what this is?
is likely to be lemon tree borer, which does not, as its name suggests,
confine itself solely to lemon trees. Satsuma mandarin trees, for
example are very susceptible to lemon tree borer. You will need
to remove the infested branches and burn them or put them in the
rubbish because the larvae will continue to live in the dead wood.
The cut ends will also
need 'painting' to prevent reinfestation. If you cut the branches
of your citrus tree in the warmer months, the adult beetle will
lay its new eggs on the cutting wound. For this reason pruning should
normally be restricted to the winter months when adult borer flight
is minimal. If you do make a cut in summer, dress the wound with
a pruning paste.
The following article
explains the life cycle of the pest and how to treat it:
tree borer and how to get rid of it
by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor
of Resource Management.
with permission from NZOOM Home and Garden content,
from the previous
The views expressed here are not necessarily those of the RNZIH