What do you think--are these spider mites? The leaf they were found on was a healthy looking leaf on a healthy looking plant, no stippling or webbing. I found them while hosing the leaf bottoms of my bush beans, because some of my other plants were looking suspicious-- slight stippling, some with a very little webbing, but I never actually saw any mites (and I've been crawling through my beans on hands and knees, with a magnifying glass, looking like a crazy lady). We had a week of high 90s-low 100s, then a week of unseasonal cool weather (70s and some rainfall)--maybe the mites were starting to take off but were slowed down by the cool weather? Would this be a good time to release some predators? Thank you!