Answer: The active ingredient in Orthene is Acephate, which is an insecticide. Using an insecticide to combat diseases such as mold, mildew and rust is a great concern!
Camelias can be attacked by scale insects. Their excrement, sometimes called honeydew, is high enough in sugar content to encourage a fungal growth called sooty mold. If your plants have a population of scales, and there's black mold on the upper sides of the leaves, I'd say the plants have developed sooty mold. The best control is to remove the scale insects (the cause of the problem) and the sooty mold will eventually weather away. One way to remove the scales is to squish them, or peel them off the stems and branches of your plants.
If you find webbing on the plants, there could be a colony of spider mites in residence. These little insects like dry conditions and you can discourage them with regular mistings (using plain water), making sure you reach the undersides of the leaves and the junctions between the leaves, stems and branches.
You'd benefit from another opinion of the problems you've found with your plants. Seek the free advice of your local Cooperative Extension office. (910-893-7530) The helpful folks there will provide treatment recommendations after a positive diagnosis of the problems.
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