Question
I have the same problem with my hanging petunias i have little green and white bugs. my camellia is having a problem as well. mottled discolored leaves and some have little white bugs on the underside of the leaves. m
My eponymous has white and brown scale that i have been trying to get rid of for several seasons with malithion and a systemic treatment. I will get the ladybugs for petunias but what about the rest

Answer
Ladybugs are EXCELLENT for scale.  My own mother had trouble with a spider plant.  By the time I got to it, it was covered every inch with disgusting little brown dots, barely a green or white leaf cell visible.  Yilkh.  It turns my stomach just to think about it.

She had been dipping it in pots of malathion for a year at this point.  Not only did it not work on the scale, it does all kinds of things to the body of the dipper because your hands end up coming into contact with it, you breathe it, etc.

I had to wait before I could use the ladybugs.  Malathion will kill them too.

But after she left it alone (by which time it was barely alive) I dropped a few ladybugs on the soil.  Weeks later, when I went back to check on things, the plant was "cured".

I had a ficus a few years later in my apartment in Brooklyn.  I don't use bug sprays so I just picked these off whenever I saw them.  The tree was hanging over the bed anyway, so I would wake up and see these little black dots appear every morning somewhere else.  And this went on for 2 years.  I could not get rid of them.

First thing I did when I bought a house was leave it outside and let ladybugs crawl up the trunk.  I think it took 2 weeks before I started to realize there were no more little black dots.

Ladybugs are voracious eaters.  They are excellent at spider mites -- white mottles discolored leaves cause number 1.  They gobble up aphids of every color and type.  But you have to NOT spray or you will kill them.

People often ask what you do to keep these beneficial insects from flying away to another yard.  It's a sensible question.  The sensible answer is, Why would you leave the dinner table to eat dinner at someone else's house?  Ladybugs aren't stupid.  They know a good thing when they have one.  And if you keep feeding them dinner, they'll move in and set up house and have children who will as any mother will tell you eat you out of house and home.  Only THEN will they fly to greener pastures.  Not a bad thing.  Bug spray doesn't last forever, either.  It just won't leave when it's finished killing all the insects.

THE LONG ISLAND GARDENER