Could be the photo but They look like some sort of spider mite to me. Spiders I believe look just like mini adults. I'd kill them

I think gardengal could be correct. As far a spiders go, I never kill spiders in my greenhouse, as spiders eat other troubling insects.

GG, you're so silly!

(I admit that I clicked to see what culinary delights were within....)

Bugs - I hate them, Mites seem to be at bay but still working on fungus gnats - soil drenches with peroxide and yellow stickies - still a few around but down.....all because I just had to drag some herbs in pots inside....

Really bad spider mite infestation.

Thanks everyone. I'll get on it. If I place the tree outside in 25F frost would that kill the spider mites.

Steve

I like your thinking, but unfortunately they can hibernate when the temp drops below 65 ... And they can withstand freezing temperatures through this hibernation... It is a fact that they can hibernate for 1 year and there is serious evidence that they can hibernate longer...

Things only get worse as the temperature gets hotter... Mites thrive in temperatures over 80 degrees... They multiply at an unbelievable rate as temperatures pass 80 degrees...

Start of with a strong spray of water to physically remove as many as possible. Then move to horticultural oils to smother what's left. Treat every couple weeks. Keeping plants cooler, under 60 degrees, will discourage mites.

I've had mixed results with Neem -- can be hard on them.