A sample of broad mites from primocane blackberry was dropped off at my office a couple of weeks ago.  The mites are quite small (much smaller than twospotted spider mite), were found colonizing the younger emerging leaves of the plant and apparently giving the leaves a rumpled, curled appearance something similar to what one might see from very light Round Up damage (Photo 1 below).

As per the UC IPM guidelines, populations of broad mite tend to be most severe in warm, humid conditions such as those found in greenhouses.  Which is a pretty spot on description of the weather we have had for like the last 10 weeks.

Also as per the UC IPM guidelines, the broad mites here are yellowish in color, and some (the females) have a white stripe clearly visible on the back.  The eggs have distinct dimples on them (Photo 2 below).

The association with primocane blackberry is of interest.  Looking back through my files, I see a communication concerning broad mites on the same in the Southeastern US, and I've been getting some calls and texts here in the area again regarding broad mites on local primocane blackberries, both public and proprietary.