If you’re trying to identify a “blue” (subfamily Polyommatinae) make sure to get a photo of their underside, where most of their field marks are… that is, if they’ll let you. They are very active fliers that don’t sit still for very long. The Northern Blue looks very similar to the Melissa Blue, but the Melissa’s orange marks are larger and bolder. The Anna’s Blue usually has weaker marks on the underside, while the Acmon and Lupin lack orange on their forewings.
The next batch of these blues will overwinter as eggs on host plant stems and in debris on the ground beneath. In late spring the eggs hatch. Larvae mainly feed on plants in the heath family and are protected / tended by ants who feed on the larvae’s sugary secretions.
Photo by: Glenn Marangelo on 7/6/21 near Florence, MT