Left to their own devices you will end up with just a few very plump dragonfly larvae. They are ambush predators hanging out in shallow waters often among the aquatic plant foliage

If you can see the dragonfly larvae easily, snip the dragonflies in half with a pair of scissors, the fish get their turn, to snack on the dragonfly

You have created the perfect food source for dragonfly larvae. If you do choose to engage the battle, be prepared for a war that you can never actually win, and you know how frustrating that can be. There will always be more larvae. Perhaps an outdoor pond isn't the best place for guppy breeding.

You could scoop them up with a net. Place in big enough water container with plants, feed them some fish food and wait for them to become dragonflys. It might work yes?

Lisa

Dragonfly Larvae will eat smaller fish. Goldfish and Koi are susceptible when young, but get their revenge as adults. I've seen goldfish devour larvae during my spring cleanings. I think Larry is correct about your guppies. Kind of a no win scenario. Add some goldfish and you would no longer see much larvae, but the goldfish would eat the guppies.

Dragonflies do eat mosquitoes. They also eat pollinating insects such as bees. Nature requires a balance.

The YouTube video below demonstrates what what can happen to small fish.

Here is a link that might be useful: Larvae Attack

Hi
I wouldn't worry too much about the guppies lol. If you keep the water that warm you'll have more offspring than the pond can handle anyway.
I"ve kept platies and swordtails since 82 and except for a freak freeze have never had the population decline.
Last August i cleaned out my small inground because it developed a leak and quit counting when I got to 400 fish lol. This is in spite of herons dragonflies cats raccoons kids you name it lol. gary

Nymphs are visual hunters and your pond seems to have great clarity. Do some hunting of your own by setting bait: A glass jar filled with pond water and a portion of (choose-guppies, brine shrimp...) and place it in some visually and net-accessible, open space at the bottom of your pond. Use cheesecloth or fine mesh screen and a rubber band to keep your bait in the jar.
Get a six pack, a chair, a net and watch for curious (or rather, always hungry) nymphs gravitate to this banquet.