I'm backing off on the ID since I really have no idea how (or if) c. ladon can be differentiated from c. lucia strictly by photos and without analysis of scales of upper wing based on wright's work.
I had forgotten that the currently accepted (for now) ID for early spring records is c. lucia and not c.ladon. Best to just leave this as "holaractic azures"!
On Black Cherry (Prunus serotina). The Black Cherry Gall Azure Caterpillar mimics the Black Cherry Leaf Gall (Eriophyes cerasicrumena). The galls are home to small mites that feeds on the black cherry leaf. It turns out this caterpillar has a fondness for the galls - it eats the galls, mite and all. It’s one of only two caterpillars in our area known to be carnivorous. (The other is the caterpillar of the harvester butterfly.)
Fresh individual. This one seemed to represent the majority of the Azures flying locally today.