Dear David.
What you are describing is precisely the way I would/do describe Varroa
infestations when I speak on the subject. Both unusual "smallish" out of season
swarms, deformed,
hairless bees, etc.
Your wingless bee that "fell on your lap" (figuratively) is a typical example of
the type of bees that one sees around colonies with Varroa infestations.
Definitely, there should be a colony in the neighborhood where you were because
these bees can hardly fly at all.  One good possiblity is that the one "wingless"
bee was being discarded by one of her sisters and it just happened to be dropped
at you site, or that its carrier dropped it at that very moment.
I am going to attempt to send you a digital image (provided to me by a very dear
friend)
comparing bees affected by Varroa mites to a normal bee. Please let me know if
you have trouble receiving the image.
Best regards.
Dr. Rodriguez