North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

When these sorts of mites affect grapes, as Dr. Dahl says, they only cause cosmetic damage and can be ignored.  Usually native predator mites build up and control them, or if the vines are treated for powdery mildew, the sulfur used as a mildew control also kills the mites.
-Lon Rombough
Grapes, writing, consulting, my book, The Grape Grower, at http://www.bunchgrapes.com  Winner of the Garden Writers Association "Best Talent in Writing" award for 2003. 
For even more grape lessons, go to  http://www.grapeschool.com
For growing supplies and more;  http://www.grapegrowersolutions.com

On May 31, 2007, at 5:56 AM, mIEKAL aND wrote:

In reference to the thread circulating the last few days, I sent photos of the red & green spikey growths on the leaves of my beach plums.  (& from Shirley's description, I believe this is what is on her grapes.)

~mIEKAL

Begin forwarded message:

> From: "Dahl, Robert A - DATCP" <Robert.Dahl@datcp.state.wi.us>
> Date: May 31, 2007 7:34:38 AM CDT
> To: "mIEKAL aND" <dtv@mwt.net>
> Subject: RE: Can you identify this?
>
> Those are eriophyid mite galls. They are only cosmetic and don't affect
> fruit production. Not much to be done about them as they are cyclical in
> populations. You don't know from year to year whether they will be
> prolific. Just enjoy the red galls they make, they are kind of
> beautiful.
>
> Robert Dahl
> Chief, Plant Protection
> Wisconsin Department of Agriculture, Trade & Consumer Protection
> PO Box 8911
> Madison, WI 53718
> Phone: 608.224.4573
> Fax: 608.224.4656
> Email: robert.dahl@wisconsin.gov