Plums are not something I talk a lot about but I do grow a couple dozen trees. Like with all of my fruit trees I check them after dark to see who the night shift is. These moths may look a bit more like ufo’s than moths but help me identify them if you can please, Are these pollinators doing their job and minding their own business? Are these the bad guys laying eggs to hatch in my fruits later in the year causing drops from a larvae worming around in my developing fruit? It’s not easy taking pictures in the dark so please be forgiving of the poor quality
Images are too blurry for specific ID, I can’t see any moth in the bottom image. The outline of the moth is similar to those in the Noctuidae family.
Some moths do use nectar sources, I doubt the trees in your picture are leafed out enough for egg-laying activity.
Try to capture one of these moths, place it in the fridge or freezer, then take a better picture for ID.
The smaller one with the intricate pattern is a pyralid moth of some kind; the larger dark moth is indeed a noctuid. Both families include many pest species.
It is not necessary to picture them so close up, clarity is more important than size; there should be enough information in the smaller moth image, but I could not find a good match in various moth ID plates – many of these moth species are variable in appearance by region.
Perhaps they would be attracted to traps hung in trees.