On Wed, 26 Mar 2003 10:30:28 -0600, "cat daddy"
wrote:


"Terry Horton" wrote in message
.. .
On 25 Mar 2003 20:23:11 -0800, (ratSenoL)
wrote:

One of my baby Monterrey oaks is just covered with little bitty green
caterpillars, and I presume they are the ones responsible for the
holes in the new leaves. We sprayed it with rather diluted Ivory
liquid soap, but they don't seem to be leaving. Is there something
else we should be using, preferably low to nontoxic in nature? Or are
these one of these pests we should try to ignore as they really don't
do that much harm (not sure hubby can do that!)?

Trees and shrubs evolved in the presence of caterpillars and are
well-adapted to recovering from the damage they cause. But if the tree
is stressed already or if you're losing a fairly large amount of
canopy (say 30-40%) you might consider spraying with BT (Bacillus
thuringensis). BT is an microorganism that infects only caterpillars
and is completely non-toxic to people, birds, other beneficial
insects, etc. Last year I used it for a Texas mountain laurel whose
top was being laid bare by Pyralid moth caterpillars; one application
was all it took.

Caterpillars are of course young butterflies and moths, and are a
critically important food source for wildlife. So when my little
Texas kidneywood is heavily grazed by Southern dogface butterfly
caterpillars each year, I leave them alone. The tree always comes back
and looks beautiful, and we get butterflies in the bargain.

I never saw the tiny caterpillars that ate my oak tree turn into moths or
butterflies. For years, they so decimated the tree that I didn't even
recognize it as an oak tree. For most of the year, the tree appeared covered
in cobwebs and I assumed it was some kind of spider.

Webworms. Been lucky here never to have had webworms (probably can't
compete with all our other pests!)

tried watering and
feeding the tree with the hope it would become healthy and find a balance
with the pests, but it never did. Last year, I tried dormant oil and was
ineffective, so I tried the soap spray and it slowed them down. I don't use
insecticides and hoped some natural predator would move in balance out the
little devils.

I've read that if you can tear open the webs with a pole or water jet,
that birds and hornets will do the job for you.