Thank you. I guess I'll cut them back today or tomorrow to try to get rid of the majority of the leaves. I think I had them in smaller numbers last year because the leaves turned brown and dropped. That's two mysteries solved.

I see no sign of spider mites whatsoever in those images. The 'hairs' are clearly not the webs that spider mites make, nor do I see any mites or tell-tale mite damage.

I think that the little white 'moths' are probably whitefly, a very common pest of hibiscus....but I honestly have NO idea what all of that long, lustrous 'hair' is. I suspect that it's fungal.

Tell us (or show us) what it looks like after a day or two. You've taken some very good images, please continue to share them!

Not mites. Not fungual. But giant whitefly, Aleurodicus dugesii.

Here's my reply to your post on the hibiscus forum: - - - -

Wowsers! Those are great pictures of a raging case of giant whitefly.
The spiral patterns are rows of eggs.
The tiny white moths are instead the whiteflies.
The hairs/beard are produced by the nymphs (youngsters).

Far different to control than the more common whitefly. If I recall correctly, natural enemies have been introduced into several places but I don't know the outcome.

Depending upon the size of the plant, you can physically rub them out of existence.

Which state do you live in? You might call your county's Extension Service office for suggestions of how to manage them.

Here are pictures and management info from the University of CA.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7400.html

OK, thanks. It seemed like that was odd looking "web" but in the insect/arachnid world anything is possible.

I'm in Houston Texas. The Hibiscus are probably 8' tall and I've got several in an area probably 15-20' long down the back of the house. According to the Alamanac, today and tomorrow are good days to prune for growth, so I may just lop the tops of these hibiscus off to a size that is more managable and work with that. I'll have to do some more research.

Everyone, thanks for the help.

And just fyi, the hairs have looked like that (except for growing) for at least a week. I discovered them about a week ago. The majority of that stuff is at the back of the plant where the plant is against the house and gets the most protection from the elements which is probably why I didn't notice until they were comfortably entrenched.

I didn't locate any helpful info specific to TX. But you can find lots of blurbs and pictures elsewhere (especially CA & FL) with a search on google.

Here's the easy way to get to the link I posted earlier.

That you found the most dense infestation adjacent to the house gives proof to the common suggestion for "good air circulation."

Here is a link that might be useful: giant whitefly info from University of CA

Thanks for the info. I've trimmed the trees back. We've had unusually cool weather (for Houston) and lots of rain. Today is gray and rainy and cool. So hopefully these conditions will promote new growth of the plants. I'll watch the remaining leaves closely and keep on top of things. If the plants don't make it then I've learned a lesson.

I've got a cotton rose, but thankfully they haven't migrated to that yet.

That is soooo interesting! I always forget about those Giant Whitefly, having never seen them for myself. Amazing things!