Welcome to the Garden Forum,
Here's a link to information about mealybugs. I use isopropyl alcohol and a q-tip, and/or spray the plant with alcohol. Others report success with neem oil. Treating a lot of plants takes time. You never completely get rid of them, but once they're under control you know to get after them as soon as you see even one. Also treat pot edges and nearby surfaces.
http://ipm.ucanr.edu/PMG/PESTN...
Mealybugs secrete honeydew, which black mold can grow on. Get rid of the bugs and hose off the honeydew, that should help with the mold. If it remains a problem, try using a fungicide.
Always read and follow label directions!
