I see this crap all the time and this is pushing new boundary. A
Devil's Darning Needle Anax imperator Nymph (TL ~ 31) mm killed and partially consumed a Northern Bluegill Sunfish Lepomis macrochirus macrochirus (TL ~ 40 mm).

In a pond setting, wouldn't the larger BG, RES, and CC keep those pests cleaned out?

I see similar and often larger nymphs when skimming FA from near shore. I figure I am willing to give up a tadpole/small BG or three for the service the adults provide when patrolling our yard and pond shoreline for mosquitoes and other nuisance bugs. There were times I looked out the window this summer and saw easily 100 dragon flies flying all over our back yard by the pond.

Jim, do you see much predation from Belostomatidae?

I see it but is not in itself significant. Oil can be used to kill the water bugs when density high and fish small.

Bigger problem is with water tigers (Predacious Diving Beetle larvae) as they can slay a lot of fish pretty quick. They decimate prawn.

They get those in deeper water unless vegetation heavy. Green Sunfish and Warmouth get them in shallower water much better. I see them in ponds immediately after fill up and where fish density it low.

I had to move a beeyard because of similar. Number of dragonflies there well into thousands. It was awesome to seem them go after swarming ants.

That would be awesome to see!

If you could come up with a dragonfly that targets Japanese beetles you could make millions!