Hi everyone,
I have had great success using Persimilis to control spider mite.
I have used it for the last 2 years. Previous to that I had a lot of problems with my cucumbers being overrun by spider mites.
I have only released at the first indication of mites and not continuously. and it seems to work great. My cucumbers have turned into weeds fr the last 2 seasons and I am sick of eating them.
http://greenmethods.com/site/biocontrols/persimilis/
I have no affiliation with this site. It is there as an example.
I get my stuff from a grower down here.