They've appeared in Whitehall this summer as well on my neighbor's grape arbor. Have not seen one across the street in our gardens yet. They are easy to catch in the open once you get the hang of it.
In Berks Co at Seyfert I was wading a small trib and reached a spot where a honeysuckle branch was arching over the 3 ft wide creek at eye level. I would estimate that 150 lantern fly nymphs were lined up head to tail on that one branch. Have NOT seen them along other streams this summer near Colebrookdale, Pine Forge, Eckville, Albany, Kutztown, Orwigsburg, Marsh Creek State Park, Downingtown, or Nockamixon State Park.