I put the roses outside yesterday (nice warm day) and all the branches fell off. I guess it was kind of tender and got caught in the wind, so I will have to wait for it to grow out again to test for spider mites. The other plants don't appear to have spider mites though.
It is about 20 degrees C colder outside today, so my roses are back under the lights. After I put them back on the shelf yesterday I found a green worm on the floor - I sent him to a watery grave in the toilet - but none of the leaves on the other plants appear to be damaged in any way so I don't know where it came from.