I have this six foot wide and five feet tall 12 year old indoor jade plant that has tiny black spots on its leaves. Can anyone please tell me what it could be. I am currently fighting the mealy bug and think I have it under control. I was losing a lot of leaves until I sprayed it 3 times with alcohol/water mixture and 2 times with Bonide spray and treated it with a systemic Bonide powder for the soil. Now I have no idea what these black spots on the leaves could be. Please help!