g'day rick,

the ants are unlikely to do damage to the tree as such, but they could
bring in thrips/mealy bugs/scale, and infest the tree with these as
they use these bugs as a food source. so you need to protect the tree
from that. there is a gel you can buy that fruit orchardists use to
paint around the trunk and create a sticky barrier the ants can't
cross.

or you can smear vaseline around the trunk with the same effect.

the ants can be killed or moved on in number of ways, set a dripping
hose up over the nest this can move them on after about 4 days, or
flood the nest a few times a day for about the same amount of days. or
you could look on my remedies page for a variety of ant control
methods.

len

snipped
--
happy gardening
'it works for me it could work for you,'

"in the end ya' gotta do what ya' gotta do" but consider others and the environment
http://hub.dataline.net.au/~gardnlen/