permaculture

[Meg Mullett <meg@kcnet.com>]

Jay wrote:
> About a fifth of my peach trees have died this winter due to trunk girdling 
> by 
> the borer. Are there any suggestions to minimize the damage beyond good 
> soil, 
> good sanitation, and good thoughts?

Hi Jay,

You've gotten some good suggestions so far, I think.  I have a couple
more thoughts for you.

The key to controlling peach tree borer (or any insect, really) is
understanding when the insect is at its most vulnerable, - when its a
moth outside the tree and can be squashed, eaten, confused or trapped,
and when its an egg or larva still outside the tree, when it can be
squashed, eaten, poisoned or suffocated.  Once it burrows into the tree
there's not much you can do. 

There are several good extension publications out there that explain the
life cycle of the peach tree borer.  They also explain the difference
between the peach tree borer and the lesser peach tree borer.  It's
important to know which you have, because they come for different
reasons and attack different areas of the tree.  The peach tree borer
generally only attacks heathy (usually young) trees and confines its
activity to the lower trunk and ground, while the lessor peach tree
borer lays its eggs in already damaged areas all over the tree.  Since
you said "peach tree borer" I'll assume that it is not the "lesser"
peach tree borer, and confine my thoughts to that one.

According to
http://www.uky.edu/Agriculture/Entomology/entfacts/fruit/ef200.htm ,
unlike most moths, the peach tree borer moth is most active from 10 am
to 2 pm.  The same page also states that egg laying begins shortly after
emerging and lasts only a few days.  So, one idea might be to monitor
for moth emergence by using sticky traps checked daily, then once you
see they are present, setting up a misting sprinkler around the tree
from 10 am to 2 pm.  (wet wings means can't fly) Or, you might try
sticky trap paint all around the lower portions of the trunk.   You
might also try painting the trunk with some sort of clay mixture prior
to moth activity, so they have fewer places to lay their eggs, and fewer
entry points for the larva?

I love the chicken idea, and if you can do it I highly recommend it.  If
however, you're in town and cant have chickens, how about putting in a
water garden and some bird feeders and bird houses?  Lots of birds means
lots of bug and larva eaters.  Water features will attract more birds
and insects as well as my personal favorites; toads and frogs.  Did you
know that a large toad can eat up to 1000 insects in one day? The
average small toad typically eats over 30,000 in a growing season.   I
don't really have a pond yet, however the pigs we keep each year tend to
dig one out for each year, and their wallows are always full of toads. 
Every place that I water often I put hollow logs, broken upside down
flower pots, or even just rocks stacked to create a dark damp place for
toads to get out of the sun.  Encouraging toads under your trees might
help with borer control.

Also, I know this is counter to many other publications, but I prefer
not to not clean up too much underneath the trees.  Having some tall
weeds and wild places encourages orb or garden spiders (Argiope), which
also are amazing little bug eaters.

I guess what I'm getting at is that if you've got a healthy amount of
birds, amphibians and predatory insects already in your garden, when the
borer moths emerge and when they hatch from their eggs, they'll have
less of a chance of making it into the tree.

All that said, peach tree borer is a serious pest, and is very difficult
to control, even with poisons.  Peaches in general are a difficult tree
to grow successfully.  They have a number of serious insect pests, and
are prone to a number of diseases and injuries that are difficult to
control organically, let alone in a "permie" way.  My personal choice is
to not try to grow the more difficult fruits, but concentrate on more
hardy native fruits that fit my "no poison and not much care" growing
lifestyle. :)

Hope this helps, and at least provides some food for thought.

Meg in KS