Two notes in response to a question about Symphylans in organic raspberries:
I have studied symphylan control in asparagus, and settled on a program of flooding the soil and treating the soil with a pesticide - the most promising one of dozens tested (including botanical pesticides). Of the natural control materials, the most promising could be parasitic nematodes.
I suggest you "Google" symphylans. There are scores of articles on the web. I also suggest you collect some specimens and submit them to the agricultural commissioner for help in identification.
Duncan Carter
I have worked with symphylans a little. As root and organic matter feeders, they thrive where there is raw organic matter in abundance. I have seen them from applications of oak leaves to gardens, and on a much larger scale from raw grape pomace applied to the soil. Using fully composted OM (from a commercial facility that turns windrows & reaches 140 degrees F) instead of raw OM would help.
Also, check the calcium content (not pH) of the soil. A constant, abundant supply of calcium is needed for root tips to grow & replace dying roots; since the crop (raspberries) is trying to produce canes & berries, it can easily be stressed for Ca, which enables the symphylans to stress vines even more. Gypsum should used to raise the Ca:Mg ratio to about 6:1. This will supply calcium without raising pH.
A treatment that should work well is predacious nematodes, applied through the irrigation system. Neem formulations may also be effective.
UC Santa Cruz has had problems with & researched these:
Monitoring guidelines are at: http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1008&context=casfs
Other info at: http://www.attra.ncat.org/attra-pub/symphylans.html#manage
Neither of these sources use the nutritional angle; thus are not truly "integrated" approaches.
-- Gregg Young, M.A. Certified Professional Agronomist Environmental Scientist