We know that fish eat bugs. So perhaps you've thought, "Too bad there isn't there a 'mosquitofish' I could put in my water garden to eat mosquito larvae." Well, believe it or not, the mosquitofish isn't a mythical beast, a benevolent creature found only in our dreams, like the mermaid. There really is such a thing as a mosquitofish!
I'll have more to say about the mosquitofish below. But first, let's consider the role of mosquito larvae in our war against West Nile virus.
Successfully killing mosquitoes is based on a simple yet important observation. When mosquitoes become adults, they rule the skies. Locating and killing winged bugs is difficult. Let's face it: the bugs are small and the sky is big. It's like trying to find a needle in a haystack.
Consequently, mosquito control that focuses instead on killing mosquito larvae or depriving mosquitoes of breeding grounds makes a lot of sense. If you can eliminate sources of standing water on your landscaping (in which mosquito larvae are born), you're hitting mosquitoes where it really hurts. Or else you can kill the mosquito larvae while they're still confined to the water. They're sitting ducks while they remain wingless, swimming in an artificial pond, say, or a swimming pool -- because they're in a medium (water) that is contained in a finite, easily-managed area. This is the time to kill them! And you can even do so without resorting to chemicals, if you prefer, for instance:
- By using Bt bacteria (Bacillus thuringiensis), which attack mosquito larvae but pose no threat to other life forms.
- Or by acquiring the eaters of mosquito larvae mentioned above, the aptly named "mosquitofish."
But before considering ways to kill the larvae in areas of your landscaping where you intentionally keep standing water, let's look at some of the sources of standing water that you might not immediately think of:
- Water buckets and rain barrels.
- Bottles and cans.
- Empty plastic pots from the nursery and other concave odds and ends you threw in a pile behind the garage.
- Old car tires (notorious rain-catchers).
- That wheelbarrow you've been meaning to bring inside, as soon as you fix its flat tire....
- Boat tarps or pool covers in which water can puddle.
- Uneven areas in lawns or gardens where irrigation water can collect.
- Clogged rain gutters and clogged drains.
- Birdbaths and water bowls for pets.
- Seepage from septic tanks.
But that still leaves the standing water that you wish to keep, such as that in swimming pools and water fountains. How can you kill the mosquito larvae which may be lurking in these places?
- Keep swimming pools clean, aerated and chlorinated.
- A bacteria called "Bti" (Bacillus thuringiensis) is often used for mosquito larvae control in standing water.
- Aerate artificial ponds.
- Avoid the temptation to mass aquatic plants together excessively in artificial ponds (mosquito larvae can hide from the fish if the vegetation is dense).
- Stock artificial ponds with fish that eat mosquito larvae.
But which fish are the best eaters of mosquito larvae? Minnows and goldfish are common denizens of artificial ponds, and they do a fine job of eating mosquito larvae. But another fish, Gambusia affinis, has acquired such a reputation as an eater of mosquito larvae that it has been nicknamed, "mosquitofish." Contact your local municipality regarding the availability of mosquitofish in your area. Formerly an obscure species, the mosquitofish is now enjoying the limelight due to the West Nile virus' invasion of North America.
I never thought that a fish might save my life....