The non-native ones are more orangeish or brown while the native ladybugs are red. And the non-native ones have varying amounts of spots. Some are solid orange or brown with no spots at all.
They exude a foul smelling liquid that stains walls and causes allergic reactions in many people.
The ones that were purposely introduced by the U.S. Department of Agriculture were in Pennsylvania where most did not survive the winter. The invasive ones in this part of the country spread from New Orleans, probably coming in on an Asian cargo ship.
Maybe this "global warming" we are having will freeze the suckers.