?? Some kind of insect eggs? Several on needles in Eastern White Pine. In urban park.
This Barklouse was on a stick I was photographing. I didn't notice it at the time.
Identification by @benarmstrong and @zdanko. Thank you both!
These photos were edited to have an Auto White Balance in Photoshop. Photos 1-5 were sharpened.
Host plant observation: https://www.inaturalist.org/observations/168047884