New Pond full of mosquito larvae

[Troppofoodgardener]

We've finally filled our pond, and lo and behold, mosquitoes have been breeding in it

What is the best way to counteract their larvae? Grow certain types of plants?

I know some fish eat mosquito larvae.. does anyone know of types of fish that would do well in tropical conditions? And what's the best way to keep the fish from being eaten by potential predators? Our neighbour has cats and there are also a few birds that visit our garden.

[Kisal]

I haven't had a problem with mosquitoes breeding in my ponds, but that's probably because there is a pump that keeps the water moving. There are undoubtedly some mosquito larvae in the ponds anyway, but there are also many dragonflies and other resident pond dwellers that prey on them.

There are fish you can add to your pond that eat mosquito larvae -- the Mosquito Darter is one I have heard of -- but I recommend that you try to find a species that is native to your area. Various frogs and toads may take up residence in and near your pond, too. It just takes a little time for the natural ecosystem to establish itself.

[rainbowgardener]

Agree with Kisal, it is going to be very difficult to keep your pond free of mosquitoes and algae unless you have moving water, like a pump and fountain.

You can get "feeder" fish that will eat the larvae, very cheaply (at least here in US you can), like a quarter each or something, so even if some of them don't make it, you haven't lost much investment.

Predators were getting our goldfish, until we added shelter for them at the bottom of the pond, something like the lantern or cave shown in the link below, that they can swim in and out of:

http://www.petsmart.com/family/index.js ... Id=2769124

they are made for aquariums, but it worked fine in our pond too.

In the meantime for the mosquitos, you can get mosquito dunks:

http://www.planetnatural.com/site/mosquito-dunks.html

They contain a variety of Bt, a bacterium that attacks only the mosquitos. It will not harm your fish or anything else in the environment.

[thanrose]

I have live-captured some Gambusia holbrooki here in the southeast US. Pond edges. They are too small to attract raccoon and oppossum, but are very efficient at eating mosquito larvae. Goldfish will too, but they are more attractive to predators, and produce a lot more waste that necessitates cleaning the pond or tank more.

My gambusia had a natural planted tank indoors with a slow bubbler, but my ex introduced them to his backyard manmade still pond on my advice. They were successful and entertaining there, maintaining a steady visible population on our year round mosquito production.

I see from Wikipedia, not always the best source, that Gambusia holbrooki or mosquitofish are now invasive in parts of Australia. The same wiki entry states that Australia does have native species of small fish that eat mosquito larvae.

Eastern mosquitofish were introduced to Australia to control mosquitoes, when in reality various small Australian native fish were already keeping mosquitoes to a minimal level.[citation needed]

They are aggressive, fin-nipping harassers of other fish and pose a serious threat to native Australian fish and aquatic fauna. Negative impacts on rainbowfish species and at least one frog species have been documented. Several rainbowfish populations appear to have become extinct due to the impacts of introduced Gambusia.

I only searched for a few minutes but did not find just what species you may have that would be better. Dragonflies and frogs are two other larvae predators that might work for you. I described the gambusia more for an example of what works for me here. If I were suddenly transplanted to Australia, I'd look for similar niche species.

[applestar]

By far the easiest thing to do is to get the "feeder" fish from large chain pets shops like rainbow gardener said. At Petsmart (there are 3 within easy driving distance for me), I can get goldfish or "minnows" for 13¢ each. they even have some colorful ones with white and black markings.

The goldfish is extremely hardy and grows from the purchased 1" size to 3" or so by the end of the season. if they manage to overwinter (rare due to my water structures being too shallow, but they occasionally survive in my Dad's deeper pond) they'll get to be 4-5".

I've also tried putting American bullfrog tadpoles but I can't provide the right habitat for the adult frogs to hibernate and survive.

By the time mosquito larvae are rampant, I've noticed other waterbugs in the pond that are supposed to eat mosquito larvae. I tried once to see if I could wait until dragonflies also started breeding and had hoped that some of the local toads might find us, but I couldn't in conscience let the mosquitoes multiply while I waited for them to naturalize. so I had to give up and went with the goldfish.

Something Else I tried and will definitely try again once I have a deeper and water level-stable pond is to get Bladderwort -- an aquatic carnivorous plant. I do have native Sarracenia purpurea (pitcher plant) planted along the water's edge.

[Troppofoodgardener]

Thanks all for the helpful advice!

I had heard of Gambusia, and was thinking of getting them, but wasn't sure what their status is in terms of invasive species. Thanks thanrose. May have to research some more localised species first I think.

We were just going to get 'garden' variety goldfish (pardon the pun) in order to get the larvae under control. However, because we had placed some mosquito larvicide pellets in the pond, I wasn't sure how this will affect said fish! Active ingredient of these pellets is Methoprene. There is a warning to NOT use in water accessible to grazing livestock.

My partner was going to find a hollowed out log and weigh it down so the fish have some place to hide. Seems like it could work, I've seen them in fish tanks.

The common green tree frog we have up here is actually herbivorous and won't eat mosquito larvae! A little disappointing, as we've found these cute frogs in our backyard, and would love to encourage more of them.

I understand that it will take some trial & error to find the right balance, so thanks everyone for your tips to make a good start

[rainbowgardener]

From the MSDS for Methoprene
http://www.sgvmosquito.org/downloads/Altosid%20MSDS.pdf

Sounds like it is relatively harmless to humans as far as we know, but

ECOTOXICITY [Based on (S)-Methoprene]
Acute Toxicity: fish: LC50 (trout): 760 ppb, (bluegill): >370 ppb
aquatic invertebrates: LC50 (Daphnia): 360 ppb

That means 50% of a population of trout dies if the concentration of Methoprene in their environment hits 760 parts per Billion. 50% of a population of Daphnia, a small, planktonic crustacean important in the food chain, dies if the concentration in their environment hits 360 parts per Billion.

That means it is likely toxic to frogs (or at least tadpoles) and other aquatic creatures.

Next time try the mosquito dunks, Bt, which is only toxic to the intended target.

The above MSDS says the half life of Methoprene in water is greater than 4 wks (how much greater, I don't know). If the half life were 4 weeks, that would mean the concentration is reduced by half in the first month. Then it is reduced by half again in the next month, to 1/4 the original concentration. Then it is reduced by half again in the next month to 1/8th.
When we are worried about parts per billion, you can see that it is going to take awhile before you can put fish in there.

[Troppofoodgardener]

Hmm.. more food for thought, thanks rainbowgardener.

I'll leave the pond for a while before putting fish in there. *Sigh* maybe even drain it.

[Boomslang]

Not sure of the law on this, but I have caught a couple of small brim from a nearby creek and put them in my ornamental pond. They will eat the mosquito larva and are usually pretty hardy fish. You can always dip them out later and return them to their natural habitat.

[PunkRotten]

Gambusia (mosquito fish), minnows, killifish, goldfish, and any small native fish to your area will all eat mosquito larvae.

Most of these fish breed like crazy too, except the goldfish. So you don't have to worry too much about losing some of them. Once they get going they can sustain their populations pretty good.

[PunkRotten]

I have live-captured some Gambusia holbrooki here in the southeast US. Pond edges. They are too small to attract raccoon and oppossum, but are very efficient at eating mosquito larvae. Goldfish will too, but they are more attractive to predators, and produce a lot more waste that necessitates cleaning the pond or tank more.

My gambusia had a natural planted tank indoors with a slow bubbler, but my ex introduced them to his backyard manmade still pond on my advice. They were successful and entertaining there, maintaining a steady visible population on our year round mosquito production.

Gambusia, most minnows, most killifish, some darters, pygmy sunfish etc, all can live in stagnant water conditions. I keep fathead minnows, pygmy sunfish, and an American Flagfish in a stagnant pond and they do really well. In fact that is where they come from in the wild. Main diets are insects and insect larvae. Some of them also eat algae too.

[carabug]

Chemicals have come a long way. There are some wonderful <a>insecticides from AP Clean</a> that are food safe, so I'm sure they'd be safe around kids and pets too.

Mosquitoes suck.

[Greener-Garden]

My wife said that in Thailand, they would fill up their rice patties will betas to control insect larvae. Since you have a tropical condition pond (hopefully water is at least 80 degrees), try introducing some betas. They're awesome fish!

[imafan26]

I used guppies in the water lilly bowls. Also Bt and dunks work too.

[tomc]

Your fish & game should be able to recommend a local to you fish to use in leu of guppy or blue gill. You aint the first pond-er with a misquito problem. They may even know where to go shopping...