I have some native fish called "mosquito fish" for obvious reason. They are live bearers and look a lot like a very plain guppy but slimmer. They grow at most 1 1/2". Had them in my ponds for years. Think even if the pond freezes to the bottom they survive somehow. And no mosquito larvae anywhere.
Was dipping some nice native plant (that looked like it could be good for oxygen in the pond)when I netted a few of them. Check some of your local small streams. Just be careful you don't introduce other critters you don't want - like leeches etc. HTH. Heather
I use dunks in all my standing water except my pond... I have a little stock tank pond in which I have 6 goldfish.. they seem to keep the mosquito larvae in check there. I used to buy my dunks at home depot but they quit selling them here so I went to e-bay... bought a lifetime supply for $80! LOL I have several 20 gallon tubs I fill when it rains so use pieces in the tubs to keep the water until I use it... rain water is like gold here.
Guppies and goldfish are your cheapest option i think. My pond has a pump and filter and i dont think the mozzies would lay in there with the water movement anyway. I had lots of water lilies in tubs and had to add a goldfish to each to stop the mozzie lava and some of the algae. Hardly fed the fish and it was always fat. hehe!