Spider mites, over and over and over

 I'm having severe problems with spider mites on three plum trees which
I'm maintaining in pots until I have a place to put them in the
ground.  Nothing I have tried seems to help.  Insecticidal soap kills
the beasties off; but three or four days later, they're back.  Then I
spray them again, and the cycle repeats.  With malathion, things are
much the same.

Since the trees are not fruiting this year, I tried a systemic poison
(disulfaton); after two months of application, it seems to have had no
effect at all.

So far this year two of the three trees have been completely denuded
of leaves, and have grown back a new set.  Now they're losing the
second set.  I don't know how much more of this they can take.

I'm looking desperately for ideas on how to control this plague!

 On Sat, 28 Jul 2007 14:02:24 -0500, Jonathan Sachs


Spider mites become resistant quickly.  Alternate Malathion, mitacide,
and insecticidal soap every 4-5 days.   Make sure you spray under the
leaves.  Your problem should get under control after 5 or 6
alternating treatments.

 

Thank you for the suggestions.  I looked up "miticide" and found that
there are several different varieties: methoprene, hydroprene,
permethrin, probably others.  What type would you advise me to look
for?

 

I have found spider mites to be really difficult to control with any
chemical agents.  Phisherman's rotation will work, but you need to keep
at it once you get started.  You might throw neem in the regime.  Spray
the trees regularly with water to blow off webs and mites, and various
residues.  I have used Talstar One rotated with neem and insecticidal
soap with fair success, but I no longer use pesticides in my garden,
other than insecticidal soap and neem.

There are predatory mites available which take time to become
established but, in the long run, will resolve the infestation.

I used predator mites to eliminate spider mites on Brugmansias indoors
in the winter.  There are numerous species which you can choose from,
based on a variety of conditions.  Good luck!

http://www.growquest.com/spider_mite_control_info_page.htm

 On Sun, 29 Jul 2007 04:19:10 GMT, Jonathan Sachs


Just having three different types is what you want. Your local
farmer's co-op may have a good product for mites.  I have used "MiteX"
by Bonide (a mix of cottonseed oil, cloves, and garlic), Malathion,
and a home-made insecticidal soap (from Fels Naptha soap).  All these
can be safely used on food plants.   Direct contact with the mites is
required and a pressurized garden sprayer set to a fine mist is ideal.
Use warm water to mix up your spray.  Greenhouses are particularly
subject to mass mite infestations.  Use 5X magnifying glass 2-3 times
a week looking under young leaves.