They are based off of ladybugs, I don't recall if it was ever stated exactly what kinds, the name guides just have them named after their general colors. These would be my best bets on the exact type of ladybug though.
Convergent Ladybug
14-spotted ladybug
Twice-stabbed ladybug
Eye-spotted ladybug
13-spotted ladybug
Epilachna undulata? This was the closest one I could find to that type of pattern, though it still doesn't seem to match. My digging didn't find any other ladybugs similar to this