Why the leaves are turning black, yellow, a little orange, and rusty looking. Crispy to touch and then they fall off. What can I do? Bugs I think maybe, but I have tried spraying. It is like it is spreading from one to another. Is it bugs or something else? Please help me out.
It sure sounds like a double fungal attack to me. I would spray the rosebushes down real well with a fungicide. Make sure that the fungicide lists black spot and rust on the label as funguses it will control. Sounds like a bad case of it so you will likely need to spray the rosebushes 3 or 4 times at 7 to 10 day intervals. In some cases Black Spot fungus can be a real tough customer and you will need to buy a more heavy duty fungicide to gain control. The one I use I get from a website called http://www.rosemania.com. It is called Mancozeb. It does leave a yellowish powdery residue on the foliage as that is part of how it works. Take a look at this article link too: https://www.gardeningknowhow.com/ornamental/flowers/roses/black-spot-roses.htm
If anyone has been spraying weed killer nearby, this damage could also be caused by spray drift. If it is affecting several roses all at once, then it could also be the spray drift problem. In the event of spray drift, the damage will likely get worse before it gets any better. All you can do is to wash the foliage off real well and water the rosebushes heavily to try and help the roses flush out the toxin. If they got a heavy dose of it the rosebushes most effected could die and need replacement.