Comma

I watched this Comma basking in the sun for quite sometime. Every couple of minutes it was swooped on by a Silver-washed fritillary (SWF). Eventually the Comma took refuge, first on my camera lens, then on my arm and finally on my shoulder. The SWF continued to launch itself at both of us and I decided to move on, accompanied - like a pirate's parrot - by my friendly Comma. Eventually it gave up and flew away. Are SWF's territorial?