David E. Ross wrote:
motor man wrote:
We have a mature tree that during about three months ( we were on
vacation) has lost the bark on parts of the tree. It looks like
something has eaten the bark away and the tree is dying above the
damage. Before cutting the parts off i would like to know what is
causuing the problem so I can prevent it elsewhere. I can send a jpg if
anyone can help on this urgent problem.
Thank you.
PS the tree is in Santa Barbara CA.


Even without a picture, I strongly guess that the tree was attacked by
brown snails (Helix aspersa). This is a serious problem in the
commercial citrus orchards here just south of you in Ventura County.
They climb lemon trees and eat the bark, leaves, and fruit. They can
kill a tree by girdling the trunk (eating the bark off completely around).

There are several ways to control brown snails. See
http://axp.ipm.ucdavis.edu/PMG/r107500111.html.

I would start with a combination of copper and poison bait. Use copper
foil as recommended in the above Web site; I have also heard of using
copper mesh. Use the bait through February. Hand pick any snails that
are up in the tree; carefully check for small, young snails that might
hide in the leaves.

In the spring, feed the tree well to promote new growth. The injuries
should heal, but it might take a year or two. Keep checking the copper
to ensure it wraps around the tree without cutting into it.

In April, when the bait has not been used for at least 6 weeks,
distribute canivorous decollate snails (Rumina decollata). You may have
to hand pick the brown snails for a year or two, but the copper should
protect your tree.

-- Thanks, David, for this .. I cannot see any snails but I did put a mulch around the tree (oops!!!)
and it was from an unknown source so may have had snails in it. I use
Sluggo and this keeps the snail population down. I will go out and look
at night to see if I can find the beasts.
I noticed that there are ants that seem to be eating at the newly
removed bark. I will use some kind of physical barrier, tanglefoot? on
the trunk and also a copper spray .. hope this does the job. The
problem in using the decollata snails seems to be that this means I
cannot use sluggo and waiting several years fro the decollatas to
become established also is too long. Sluggo seems to be safe and not
harmful environmentally but I am open to more comments on this.