I was a little surprised this year that I've only taken 45 pictures total in this catagory. I did do more videos though.
Bees working an apple tree in April.
Wasps or some Mountain Mint in July.
More wasps on a stunning specimen of Swamp Milkweed, Asclepias incarnata.
a video on youtube showing this aspect off. Some species of Ichneumon wasp specialize in caterpillars, beetles, or mason bees.
Cup Plants are notorious for having flowers that do that even on the same plant, between flowers growing next to one another.
Some Honeybees working Liatris microcephala. This was at a nursery I was touring. The overpowering music was great to drown out the sounds of the tour guide talking.
Lastly who could forget the massive goldenrod plant I have. The species is Solidago altissima, Tall Goldenrod, and it's a food source to just about anything that's alive for the first frost later to come. It's also a good nectar source for next years queen bumblebees; one is featured in the video at 2:35.