Sorry for the situation....but good photos!! Not sure if that IS a mite or not.....but I didn't think jades in general were real susceptible to them. Do you see any of the telltale webbing....perhaps where the petiole meets the stem?

Kevin, do they leave a trail of red stains if you squish them? If they do, those are probably clover mites.. I believe clover mites are harmless.. and they usually appear during the cool temps of Spring/Fall from the creaks and cracks of concrete buildings.

http://forums.gardenweb.com/discussions/3075312/clover-mites-invasion

I've never experienced red spider mites before, but these nasty critters disseminate foliage very quickly, I've heard them destroying plants in a matter of days..

Have you tested imidacloprid on mites? I do know if we use gritty mix, we need to feed the plants with more imidacloprid, because they don't absorb it as quickly..

If it's spider mites, I hope you get this pest under control..

The damage looks very much like oedema - the raised surface. I'm not sure what the specifics of spider mite damage normally looks like, though. Oedema is caused by cells bursting - I would think mite damage would look more like craters rather than mountains, but, really I have no idea.

I just searched and couldn't find it (too many jade threads), but there was a thread not that long ago where a few members shared similar issues with tricolors (similar looking brown damage...), both Rina and Crenda I think, in the end there was no conclusion other than "maybe oedema". But also no magnification like yours :)

I find too much magnification as hard to use as not enough, but there is a wide variety of "usb microscopes" (wide price range) that make it very easy to get high mag pix if you really want to scratch that itch.

I use neem almost exclusively now - haven't hit mites with it, but did receive a mealy-infested plant in the mail that I managed to completely save with 3 applications of neem, 5 days apart. Have read it is also effective on most mites. If you want a more sure/chemical answer, bayer 3-in-1 has both imidapclorid and a miticide, safety caveats apply.

Daniel

Woodnative - I couldn't find any webs near where the petiole meets the stem. I'm not sure about susceptibility, but I never had worried about it before. Thanks for the comment on my photography! *laughs*

Bernard - I think these are much smaller than those that you had. They're so small I'm not even sure how to squish them!

Imidacloprid doesn't work on mites (and they are not listed for Bayer Tree and Shrub). Unfortunately, I do not have access to Bayer 3-in-1 here (which does contain miticide). That would have been a good option though.

Daniel - The raised/damaged surfaces had me wondering. I've read that spider mites can/do cause leaf disfiguration, but I wasn't sure what that disfiguration would look like on a Jade.

I do remember all the brown damage discussions we had with Rina and Crenda, which is why I originally dismissed this issue. But then on *very* close inspection, I saw the red mites and wonder if maybe we all are having the same problem!

My 60x-100x magnifier was nearly impossible to use... it took me maybe 10 minutes to just get it focused in on one mite to get a good up-close look. I think mine is just terrible quality (and they are hard to use in general).

I've just put in an order for a 40x loupe with LED (will arrive in a month or so). It should complement my 30x loupe nicely (which I would recommend for others to buy). As an aside, I've found that my 10x and 20x loupes are convenient, but not that helpful for up-close inspection.

I think Bayer 3-in-1 (with cautious, judicious use) may be next on my list of things to get in the spring. I'm carefully logging any plants that have been treated so I can minimize pollinator impact.

Daniel

You are right, I have mentioned the dark spots and have them on many of the Tricolor plants. But it is very different what Kevin is showing now. The spots are almost like a dried-out tissue, so it would make sense that their cause is oedema? Some have even little cracks - like a dry clay soil would. I don't worry about those at all as it was mentioned that this variegated jade seems to be prone to it more than other jades, any quite a few ppl said they have them too. They don't seem to disappear, but don't spread around either.

I don't have way of taking a close up, here is just one example of the spots on some of my plants:

They also appear on 'albino' leaves - the 'cracking' is visible on the leave on lower right (but not all of them have this kind of surface - the larger spots seems to):

None of my pictures were good closeups, and these taken today aren't much better. But I do believe mine had edema. Makes sense with our overly wet summer and high temperatures. I dried them out and the new growth looks good. It did not spread, so I lean toward edema.

neem wise I've used dyna-gro cold pressed neem mixed at time of use - effective but VERY strong odor. For the last 3 months I've been using Azatrol (similar to Azamax, but a bit cheaper for me to find), which is a neem extract that has a much higher concentration of azadirachtin than dyna-gro, and smells much much much less (still unmistakable whiff of neem, of course, but I get no complaints when I use it indoors). It has 1.2% azadirachtin vs ~ 1500ppm azadirachtin (0.15%) for Dyna-Gro (not published that I can see, but I called and asked).

Cold pressed neem has more good stuff than azadrachtin, so it's debatable what is "better", but so far I've had great luck with Azatrol and I no longer get stressed out about spraying it indoors due to odor. Azatrol also emulsifies easier in my experience, not sure if it has an emulsifying agent included or not, I mix it with a small amount of peppermint castile soap anyway - helps as surfactant (sticking to leaves - hope thats right use of term). I don't use alcohol in my neem mixture myself, it seems to act the opposite of a surfactant and neem has all the pest killing power I need.

Daniel