Garden Pests and Diseases: Foliar Nematodes or Fungus??? My Rex begonia is dying..., 1 by DeanSwishhh

DeanSwishhh wrote:
My Rex Begonia is dying. I thought that it was bacterial or fungal but I may be wrong. The leaves keep disintegrating and the plant is literally disappearing week by week. I have 2 of them in pots outdoors about 3 feet away from each other. I was planning on bringing them inside once the weather started getting cooler. The one is def. going to die but I was wondering if there is hope for the other one. I need to ID the problem.... Is there someone that can make a positive ID? I attached 4 photos. I would really appreciate feedback.