This improbably coloured moth with the big green eyes, is found almost entirely on the native plant, evening primrose (Oenothera biennis), as here. Occasionally, you will see them on other flowers, but invariably they prefer the evening primrose and will sit during the day, with their heads stuck inside the flower. This was one of two moths inside the flower head, but I disturbed this one when I held the plant to keep it from blowing around. At that point, the moth popped its head out and walked to where you see it in the photo. Looking closely at evening primrose flowers once they start blooming, will usually provide you with a look at at least one of these vivid moths.