"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.

And the birds get food.