Here's another novice identification request.
Lake shore. 23rd of September. A small pack (~5-6) of these stopped nearby when I was taking macro photos. They didn't seem to mind my presence, but it took me a while to get my camera ready and this is the only photo that I managed to get before they flew elsewhere.
I've browsed several books and can't find this one. I'm probably overlooking something obvious, possibly because of the angle..