I have been fighting the persimmon psylla for five years now. It
took me a couple years to even figure out what it is since it is
uncommon, then a couple more to figure out how to control it to any
degree. At this point I can generally keep it in check but it
requires more work than I would like to spend on it. The main
problem is the psylla curls up the edges of the leaves and creates a
little cocoon in which sprays do not reach.
I am generally an organic grower which mostly limits myself to oil
and soap and the like. Here is what I have tried that works: soap
and oil sprays both work, but for the curled leaves you need to
manually uncurl them with one hand as you spray with the other hand.
Another thing I have done is at the same time as a spray to tip all
of the new shoots, which is where the psylla like to lay eggs the
most and where it is hard to spray thoroughly. It also gives the
flies no good egg-laying spots for awhile. I also remove the edges
of infected larger leaves. If a leaf is badly damaged I may remove
the whole leaf. This is faster than trying to unfurl and spray it.
And occasionally I get desperate and spray malathion, no more than
once per season. Lately I have been experimenting with Surround
which is known to work on pear psylla so I thought it may also do
something on persimmon psylla. It does seem to have some effect, but
the new shoots grow very rapidly and so very frequent sprays are
required to keep them covered. Also the flies seem to have a knack
for finding the one little spot that was missed with the spray and to
put the eggs there. I plan on continuing my experiments with
Surround since it may have some promise.
Has anyone found a good, permanent, preferably organic treatment for
this pest? I am surprised how little I read about it yet how
difficult it is for me to control.
Scott
[NAFEX] Control for persimmon psylla?,
Scott Smith, 06/05/2007