Dragonfly larva?

Dragonfly larvae are quite different to that. Those look more like mosquito larvae, the first stage, or what we call wrigglers.

mosquito dunks should take care of that. Harmless to fish and plants, they contain BT bacteria that kills mosquitos.

Thank you! I was thinking of getting some goldfish to let them eat them. As an organic way to threat the "problem".

goldfish is a good idea. :)

Unfortunately they were eaten after 3 days :( poor goldfish. But small birds know that the larve is there, so they eat them when they are on the surface.

So I just let nature take care of it ;)

I bought 2 goldfish, one orange one black. The orange one got eaten, the black one survived (found out 3 days after the attack). So now there is only 1 fish left, I don't mind it. He can eat the larve and algae and stuff without doing too much damage to the organic filter. But is being on his harmfull to the fish? Does he need friends? (there are frogs... too)

Goldfish like to have friends. He might have survived because he's black and doesn't show up as well as the brighter fish. Get a couple more fish, and soon they'll take care of replacing eaten fish. :)

If you have pond plants, the fish can't get to all the larvae, but the BT dunks can get everywhere.

Here on Hawaii Island, we're susceptible to mosquito-borne illnesses--Dengue, Zika, and others, (though apparently not malaria)--so it's worth making extra efforts to control the little buzzers. If it's just about itchy bites in your area, it might not be as important to get them all.