Late this summer I started emptying the hummingbird feeders into a dish for the wasps when I refilled the feeders for the birds. This provided a good opportunity to get photos of large numbers of wasps. I filled the dish to the top with the sugar mixture and by the end of the day the dish was empty. The sticks and leaves are in the dish to provide footholds for the wasps because otherwise they ended up drowning in the water. I think this photo shows all V. maculifrons. Other wasps and hornets did occasionally show up but the majority of wasps seemed to be V. maculifrons (if I am correct in my ID, that is!).