It has been so warm and dry here for such a long time that I've found a couple of plants growing outside with the beginnings of a Red Spider Mite infestation. The whitish patches on this 'pink China' leaf are it :evil: IMG_1434 by atropica1, on Flickr
I've found RSM attacking my young Sesbania this year. Last year they attacked the hirsute leaves of my Cantua buxifolia which was one of the reasons that I left it outdoors to take a few frosts - completely RSM free this year.
In the greenhouse I'm virtually RSM free now thankfully, although I did find a few on the young leaves of a cutting of Passiflora "Caprice" that I was given and an Isoplexis seedling.
Well it is a pest that occurs outside but it is kept under control by the natural predators that eat it and a climate that doesn't let the population expand too quickly, even so it causes significant damage in fruit orchards, but I have to say I also usually use the "Bung it outside" system for things like Cantua which not only always seem to get it but react to just a couple of mites like they were stricken with some dread disease!