The return of the spider mites

After several weeks of mite free living I noticed that the pepper plant in my bedroom had quite a number of mites on one of its leaves, though only limited signs of leaf damage (indicating that the mites had not been there long).

I found this rather strange as I have been checking this plant for signs of infestation for the past number of weeks and it has always come up clean. Furthermore, the mites were on one of the highest leaves and seemed to have left most of the other leaves untouched. That the mites would have hit the top leaf and left the other leaves clean strikes me as odd. Wouldn't it have been easier to hit the leaves closer to the ground?

To mitigate the infestation I have removed the most infected leaf from the pepper plant, sprayed it with insecticidal soap, and moved it outdoors. I also moved a few more of the plants from the area (my bedroom windowsill) outdoors and cleaned the window area. I am little worried that some of the other plants in my room may now be susceptible to the infestation, which had previously not affected the plants in my window. Hopefully I caught things early enough to prevent a spread of the mites.

I am really hoping that by the end of this summer the mite problem will be resolved. If not, I really don't know what I will do with some of the plants which I presently have outside that I will need to bring indoors for the fall and winter (particularly the bay tree and the banana, but also the tomato and pepper plants). Anyway, I guess, minimally, I will have to keep an eye out for any new signs of infestation.