Do you have white flies or spider mites? The webs sound more like
spider mites than white flies.

White flies will be small white moth looking insects on the underside
of the leaves. Spider mites are almost undetectable by the human eye.

In either case I'd get it outside and give it a good hoseing down.
Soapy water should do the trick for either insect. If you don't isolate
the plant they will spread to other plants.

For white flies we have good results with Bayer Advanced Garden Rose &
Flower Insect Killer but now that weather is warm enough to move plants
outside would rather deal with them in safer ways.

Marv-Montezuma, IA
http://community.webshots.com/user/vmwood