What could this be? Webbing on Pleione
 

I'm tempted to discart mites but...we never know, there are several species and I'm not experienced in distinguish them all.
The webbing has around 7 cm in length (when do you get used to go metric?;) That's about 2,75 in).:biggrin:

https://s9.postimg.cc/hb508sa9r/20180520_144122.jpg

https://s9.postimg.cc/nou3c3clr/20180520_144157.jpg

https://s9.postimg.cc/u3t4888vj/20180520_144233.jpg

Could be mites, but if there are enough of them to produce that much webbing, I think you would see them on the underside of the leaves. I suspect little spiders.

Usually, when I see long webbings I tend to think first about tiny spiders but... you never know.
So far, no red/brown tinge on white cotton.