In the Yale Experimental Watershed. Quite a large population. Doesn't show up in any of the species lists put out by Yale for the watershed. Maybe they didn't know what it was?
Pipilio cresphontes
3.5-5.5 inches
Could this be butternut? Nuts are very sticky.
Along roadside.
nectaring on red clover at Salt Bay Farm preserve
Small weed tree in chestnut orchard.