2016.05.18 Wednesday: I believe that this is a Cabbage White Butterfly ...One of the most common butterflies. Males have only one spot on their wings, while females have two.
According to my research on the web, Cabbage Whites are one of the first butterflies to be seen in the Spring, and one of the last to be seen in the Fall. They fly from late February to mid-November.
They are considered pests if one is growing broccoli, cabbage, or radishes -- but they are so beautiful gracefully fluttering around that it is hard to see them as a pest!