I have a lot of webs and spiders on my potted plants outside, but not all the plants seem to be suffering. The other day a Carolina Wren tried to get a spider, I think, on one of my cacti, and got stuck with some thorns. Well, not much I could do about that. But I was wondering if I should be trying to remove all the spiders before the plants start suffering? Are spider mites caused mainly by stress? So if I watered and fertilized more I could avoid them? (Some of my succulents can't be treated with insecticides, from what I understand) And are some outdoor spiders beneficial? I've often seen larger spiders on my garden plants and have let them be, since I didn't notice much damage being done. Thanks.

Andrea