Here is some information on the life cycle (from Ohio State):
The magnolia scale spends the winter on one to two year old twigs as tiny, dark-colored nymphs. As temperatures warm in the spring, the scales begin to suck sap and have molted once by early May. At this time two distinct forms can be found, males and females. The males remain small, about 1/8-inch, and soon turn a translucent white. Soon after the males turn white, they emerge as tiny, pink to yellow gnat- like insects with two long waxy threads extending from the tip of the abdomen. The females continue to expand and by early June, they have turned a brownish-purple color. This is also the time that they produce excessive amounts of honeydew. By July the females are covered with a powdery, white waxy coating and are turning more of a yellow- tan color. By late July and August the adult females begin to give birth to their young known as crawlers. The tiny, mobile crawlers move around until they find a suitable feeding site on which they settle down, feed, and remain through the winter.
If your black beetle is truly a lady bug (and it may be as there are many species of lady bug) it is probably there to eat some of the scale
