Your most effective method is to drain the pond. I have an empty pool in my back yard (SoCal, too), and I drain it after ever rainstorm. If draining is not a viable option (or you're too lazy), then try a product called "Bite Free"... http://www.valleyvet.com/ct_detail.html?pgguid=da753262-faa7-4c5d-8f16-13c40dfaf0a3

Im not an expert... but what if you just frequently scooped it out with a net? It may be tedious, but I think it would be what your looking for if you want to keep the pond.

a splash of diesel will create a film across the top of the water killing mosquitoes, provided there arn't any other organisms in the pond that would be hurt by the diesel

Please, please DO NOT put diesel in your pond! There's a much safer and easier way to kill mosquito larvae in standing water: it's a biological larvicide known as BTi (Bacillus thuringiensis israelensis) and you can buy it in garden stores or even online...just search for "mosquito donuts" in a search engine (e.g. GOOGLE). All you have to do is toss a "donut" into the standing water and it will dissolve and kill all mosquito larvae for a month or so. It's easy and safe for kids, pets, and the environment.

schrocker nailed it. The diesel would work, but it's an ecological disaster. Even salad oil would work; the film blocks off the air tubes the mosquito larvae breath through. Don't use oil though. The best way is the larvacide she describes. I use it at home and it works phenomenally well. It only affects mosquitoes. Ask for mosquito 'Dunks'. They look like donuts about 2 1/2 inches across. Towns use them in the sumps of storm drains and catch basins. Home Depot and the like carry them.

Don't put any chemicals in there ! Go to a pet store and get some feeder goldfish, they will eat the larva and start a small eco-system in your pond.

Some states/counties have a mosquito abatement department. The whole purpose is to eliminate mosquitoes. They unusually will give you small fish that they raise to eat the eggs. They are usually free or for a small charge.

Put some minnows in there, like the ones you fish with.They love mosquito larva.

Ellie Mae and the cement POND.. lmao sorry.. had to

Ellie Mae and the cement POND.. lmao sorry.. had to

You can put in Gnatrol or Enstar II.