Identify This Scale?

I spied these button like bulbs on the lower trunk of a Japanese Maple in S. NJ. They are about the size of a small pea. Ants were attending to them. I did scrape them off. They left a whitish powder on the trunk. Inside they were filled with a yellow-green gel.

 

Almost like a mealy bug scale combo.... keep up the manual removal....

 

Have a look at the thread Need identity of tree pest/disease! | UBC Botanical Garden Forums.

 

Thanks Jungle.