Natural Mosquito Control?

April 11, 2007 5:43 PM

Is there anything I can spray under my patio and around the backyard that will keep the mosquitos away without poisoning the well (or my dog)?

Yes, it's skeeter season already in Texas and just like last year, it appears the little buggers are reproducing under our deck again (they're very heavy there, not so much in the rest of the yard, and our yard slopes such that water runoff tends to pool up there when we water or when it rains). I'd really like to get rid of them if I can, but I don't want to be using something that is bad for the water supply/local eco-system. I'd also really like to avoid poisoning my dog (yes she's on heartworm preventative...don't worry).

Something liquid is ideal, since in order to get it underneath the deck, we'd basically have to pour it on top (bear in mind that ruining the stain would be a major bummer). I don't mind something that I'd have to do once a week or sporadically throughout the Summer.

posted by Ufez Jones to Home & Garden (12 answers total)

Mosquito dunks aren't liquid, which might make them even easier to use: just drop them into standing water every month and they prevent the hatching of eggs. I don't know how environmentally friendly they are, but the brand I used to distribute on my parents' land explicitly stated they did not make the water unsafe for pets or swimming. I used to break 'em into smaller segments for small pools of water.
posted by Elsa at 6:22 PM on April 11, 2007

To get dunks under the deck, either toss one in at the side if there's an opening, or break it into fragments small enough to fit through between the planks (or wherever you were planning to funnel in the liquid). They're about as solid as, oh, packing pellets, or maybe a factory produced cookie, so breaking them is no trouble.
posted by Elsa at 6:26 PM on April 11, 2007

Mosquito dunks are actually a solidified form of B.T., a natural insecticide produced by the bacterium Bacillus thuringiensis that has been used for decades by organic farmers to control crop-eating insects and by the World Health Organization to kill mosquitoes without using dangerous chemical pesticides. It is available at most garden centers in a concentrated liquid form. It works by liquifying the larve's digestive system (once ingested) therefore killing the organism. It only works on insects in their larval stages, so it is usually applied to standing water that houses developing mosquitos. I think it would have to be applied often which may be annoying-- perhaps fixing the drainage problem that allows for standing water to collect would be a better long-term fix as that is the source for the mosquitos. Bt is safe for use around pets, though. And it's cheap (I think it is around $7.00 for a 4oz concentrate that would last all summer) Good luck.
posted by jlowen at 7:46 PM on April 11, 2007

I think Mosquito dunks are actually live Bt spores that infect the mosquito larva, which is different than just spraying purified Bt toxin.

I agree 100% though about trying to address the problem of standing water.
posted by Good Brain at 8:21 PM on April 11, 2007

I'd really recommend looking into mosquito magnets, if you have enough property that you can put it away from the house a bit. We lived near a marsh that had bad skeeters and no-see-ums, and the mosquito magnet did a great job at making the outdoors habitable. They are a bit expensive, though- you should canvas your neighbors to see if they work on the local pests.

The advantage to this approach is that it has pretty minor environmental effects, compared to most sprays and chemicals.
posted by jenkinsEar at 8:49 PM on April 11, 2007

The best solution would be to get rid of the pooling problem, but you already know that. A truck-load of gravel isn't expensive, although you want to make sure you don't make your drainage problems even worse by redirecting it into your house or something like that. Also, are there other sources of standing water around, liked blocked gutters, holes in the top of a concrete wall, or old childrens' pools behind your neighbor's house? Mosquitoes will happily travel a fair distance (I want to say that they will travel about 1 kilometer, but I'm not sure about that figure) so your mosquito problem is probably not coming only from your backyard. Still, prevention is a lot easier and cheaper than an ongoing control effort, so getting rid of the pools of water would be a really good idea.

Second best would be to combine using mosquito dunks with a mosquito magnet, because not all of your mosquitoes are coming from under your deck. Depending on whether you have one big puddle under there or a bunch of small pools, you may need to be creative in getting mosquito dunks into the right places. Both are dog-friendly and relatively environmentally benign. However, the mosquito magnet isn't free, and you need to buy gas cannisters to keep it running; the dunks will need to reapplied with some frequency.
posted by Forktine at 3:37 AM on April 12, 2007

Possible addition to above advice:

I was recently told about the geranium's natural mozzie repelant properties, which upon Googling needs to be taken with a grain of salt; the leaves must be crushed or pruned to release the oils into the air. This apparently goes for most of the so-called mozzie-repelent plants.

But maybe a mixture of possible mozzie repeling plants (1, 2, 3) in borders around the patio & yard? Lemongrass or what have you + active dog = crushed leaves?

Fetch, Coya! :D
posted by romakimmy at 5:02 AM on April 12, 2007

What forktine says, about the pooling. An ounce of prevention is worth a pound of cure, and all that... Where I live in the Houston area I've yet to see a mosquito.
posted by Robert Angelo at 7:00 AM on April 12, 2007

There are many good suggestions here, but one thing to add--
mosquitos are very weak fliers that thrive in still conditions. While you should do everything you can to get rid of the source of the skeeters, if you can do something to produce air flow (i.e., fans) on your deck, this will also help immensely.
posted by mcstayinskool at 7:48 AM on April 12, 2007

We just purchased a new home that already had a mosquitonix system installed. We haven't had it switched over to us for a refill yet, but their site says they use "...a natural insecticide derived from chrysanthemum flowers...". I did some searching, and it seems that you can buy the stuff on your own via eBay and the like...

For what it's worth, the previous owners swore by the system.
posted by richmondparker at 10:16 AM on April 12, 2007

Consider purchasing or making your own bat house. A single brown bat can consume as many as 1,000 mosquitos in one hour. Natural and safe pest protection at it's finest!
posted by Jade Dragon at 11:36 AM on April 12, 2007 [2 favorites]

Squirt some dishwashing soap in the standing water. You don't need much. The liquid soap breaks the water surface tension. When the mosquito lands on the water to lay her eggs, she sinks and drowns.

If only the female mosquito bites, what does the male eat? Nectar from grass and shrubs. So the cloud of mosquitos bellowing out of your bushes may be the non-human biting males. You want to focus your efforts toward the females.

Also works with fleas, same reason - lack of water tension. You could try putting some shallow pans of soapwater around your deck. This is known as a flea and mosquito trap. You will be amazed at the number of them you can drown.

The liquid soap works great. Not harmful to other animals and is a lot cheaper than the "dunks".
posted by JujuB at 8:37 PM on April 12, 2007 [2 favorites]