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Mosquito control

16 years ago

I just finished reading a very long thread from someone who was wanting to avoid using DEET to keep the mosquitoes off. Many of the suggestions were folk remedies that are either totally ineffective or mostly ineffective. Others are well documented, proven, alternatives to DEET. Since I am a freelance writer and currently working on an article on organic mosquito control, I decided to share some of my research and personal experience here and hopefully provide a comprehensive, effective, organic approach to mosquito control.

Before we start: I want to note that DEET is by far the LONGEST LASTING effective mosquito repellant. If you should choose to use it, remember, it is a chemical that is caustic to plastics and other synthetic materials. It should be used with extreme caution. Also, the concentration of DEET in a product determines the length of time it will be effective before you must reapply, it DOES NOT determine it's effectiveness (think about it, it's either effective or it's not. Mosquitoes either bite you or they don't). Roughly 25% is pretty much universally regarded as an amount that will protect for up to 5 hours.

For more information on DEET, please visit:

I mention this only because the discussion of controlling mosquitoes is incomplete without mentioning DEET. DEET is relatively convenient, relatively safe at low concentrations, and, in my opinion, the best choice when needing to avoid mosquito bites in an uncontrollable environment such as camping, hiking, military service, or other outdoor activities where you cannot control the mosquito population in your surrounding area.

Moving on. There are 2 critical areas that must be addressed when it comes to effective mosquito control. First, is population control, and second is deterrent.

Population control is achieved by killing the adult insect and/or the insect larvae or otherwise interrupting their life cycle.

Deterrent is making the insects go elsewhere for their meal.

I'll address population control first.

When it comes to mosquito larvicide nothing, absolutely nothing, compares with Bacillus thuringiensis (Bt). Bt is a naturally occurring bacterial disease of insects. in some insecticides, these live dormant bacteria are the active ingredients. In others the delta-endtoxin the bacteria produce is the only active ingredient. Either way, the insect larvae must ingest the insecticide for it to be effective. There are several strains of Bt available for use against many different types of insects. Bacillus thuringiensis Israelensis (Bti) is the strain used against mosquitoes, but for the sake of thoroughness I'm including a complete list.

Kurstaki strain (Biobit, Dipel, MVP, Steward, Thuricide, etc.):

Vegetable insects

Cabbage worm (cabbage looper, imported cabbageworm, diamondback moth, etc.).

Tomato and tobacco hornworm.

Field and forage crop insects

European corn borer (granular formulations have given good control of first generation corn borers).

Alfalfa caterpillar, alfalfa webworm.

Fruit crop insects


Achemon sphinx.

Tree and shrub insects

Tent caterpillar.

Fall webworm.


Red-humped caterpillar.

Spiny elm caterpillar.

Western spruce budworm.

Pine budworm.

Pine butterfly.

Israelensis strains (Vectobac, Mosquito Dunks, Gnatrol, Bactimos, etc.)


Black fly.

Fungus gnat.

San diego/tenebrionis strains (Trident, M-One, M-Trak, Foil, Novodor, etc.)

Colorado potato beetle.

Elm leaf beetle.

Cottonwood leaf beetle.

Bt is considered safe to people and non-target species, such as wildlife, and beneficial insects. Some formulations can be used on essentially all food crops (of course, you'd still want to thoroughly wash them before eating).

Of course, I can actually hear a few of you screaming "How is a biological insecticide organic!! It's germ warfare!" Well, that brings up the debate about what exactly organic means in this context. So, I'll just give you some facts and let you decide if it fits with your personal definition.

Bt is a naturally occurring bacterium common in soils throughout the world. Not all strains of Bt can infect insects. Even some strains that can infect insects are not lethal to the insect infected. What scientists have done is carefully isolate strains of the bacteria that are the most lethal to the specific species of insects they desire to control. These bacteria have not been genetically altered thorough genetic engineering, or other highly invasive technique. What has been done to develop these strains is much like the way dog breeds were developed. In a way, you can look at the useful Bt strains as being domesticated bacteria.

Still not convinced? Copepods (microscopic fresh-water crustaceans that feed on mosquito larvae) might be a better solution for you. Not nearly as easy to use as Bti, and not available commercially. If you want to use Copepods you'll have to breed them yourself. The following link will tell you how:

Now, those of you who aren't afraid of the mosquito-killing Dobermans of the bacterial world probably want to know, "where do I get Bti? and how do I apply it?"

Great, glad you asked. There are 2 types of Bti suspensions; liquid and dry. Each has its application, and your outdoor space will determine which you'll want to use. I can only tell you the application process I use that seems to have gotten me pretty good results, especially since my property is only 1/4 acre, in the heart of the city, and bordering a flood/storm drain stream area.

For standing water that I like to have around, like my container water garden, birdbath, fountain, etc. I use a liquid suspension. My particular brand is called Microbe-Lift BMC. Once a week I visit all my water features and apply a few drops. It's easy, effective, and doesn't disturb the larvae of insects that I want to have around. Like Dragonfly larvae.

I use dunks in my roof gutters, the water catchers under my potted plants, low spots in my yard where water collects, and anywhere else I find that I have standing water after it rains or I water my plants. These are places that it is either inconvenient to empty out the standing water, or simply impossible.

The real key is to use the right size dunk for the application. For instance, in my roof gutters I use a couple large dunks that can be wedged in there so they don't impede water flow, but still don't wash away. Thus I only have to do it when I give the gutters a good spring cleaning. I also have a hollow tree that tends to collect water, but is very hard to get to the large trunk opening 15 feet off the ground. A small colony of bats lives in this tree, and I would hate to disturb them. Thus, so I don't have to climb the tree very often, I use a large dunk that will last the whole mosquito season.

Also in the dry suspension category is a product called mosquito bits. Like dunks but granule size. About once a month I apply 72 oz of this stuff to my entire property with my broadcast spreader. I also sprinkle about 16 oz of it in my wood pile.

Notice earlier I mentioned places that collect standing water that are inconvenient or impossible to empty. Containers that can be emptied, or even better, kept from filling with water in the first place, should be. This is very important because like most of us, mosquitoes are lazy and want an environment where all their wants and needs are within easy reach. If you make the area around your house as inhospitable to them as possible, they will live elsewhere. Believe me, this works, even for a guy like me that lives next to a drainage ditch.

take a walk around your property, paying special attention to places that would hold water. Here are a few things you might look for:

Clogged roof gutters (absolute #1 mosquito dream home!)


Children's toys and bicycles

Old tires

Trash cans


Unused pots


Basement window wells

Area under your deck or shed.

Compost heap

Forked branches of a large tree


Cans or bottles

That should be a start, but I'm sure you'll find other places you wouldn't have ever thought of if you hadn't gone out specifically looking for these secret mosquito love nests. Once you've identified them, empty them, treat them with Bti, or find a way to prevent them from gathering water. Drill holes in the bottom of open top trashcans. Always store your wheelbarrow upside down. Make sure the kids pick up their toys out of the yard. Install gutter guards to keep them from clogging.

Sounds like a lot of work? it really isn't. I guarantee you I spend more time weeding, harvesting, rotating my compost heap, planting, pruning, mowing, and all the other chores of a loving gardener. Believe me, a small investment of time in eliminating mosquito habitat from your home will be well worth it. Remember, for every puddle, pool, or mini-pond you have on your property that you don't do anything about, your going to have hundreds of little blood suckers who don't have to go very far for their first meal.

Killing adult mosquitoes is much harder. That's why I spent all that time talking about Bti. Still, some of them will make it to adulthood, so some plan of action should be in place to make sure that maturity is no picnic either.

So, how to do it? Well, please stay away from the bug zapper type lures. First, they don't attract mosquitoes very well since mosquitoes aren't strongly attracted to ultraviolet light. But the new mosquito magnets really really work. I mean, really really work.

Granted, Mosquito magnets are, to say the least, about as attractive as a gas grill. They use propane, which is probably not considered organic except by certain types of chemists. But they work, are non-polluting, and harmless to everyone and everything that is not a mosquito.

A friend of mine brought his to our Fourth of July celebration last year. It was set-up in the back of his pick-up. Now, I am mosquito candy, even wearing DEET I will get bit at least once. I've even been bit through denim jeans. But, I decided to forgo the DEET this time around and prepared myself for the misery that was sure to come. We started the thing several hours before dusk, ate, played, then settled down on a picnic blanket in the grass about 20 feet from the truck to watch the fireworks display. When it was over, guess how many bites I had?


I asked around, and almost everyone else nearby hadn't been bitten either. The only people I could find that had been bitten were a father and son duo who admitted that they had been down by the lake fishing earlier.

All I can say is wow. They are expensive. But after going over to my friend's house several more times this summer, and not getting bit once while I was out there. Even when we all went swimming in his natural pool at around dusk. I am convinced and I'm buying one.

Still, considering the cheapest mosquito magnets right now run $200 to $300 dollars, we should explore a more economical ways of eliminating these micro-vampires with wings.

Of course, Lestat never had to worry about anyone 500 times his size eating him. (well, not until toward the end of the series anyway)

While birds and bats are often the most touted mosquito hunters, it's actually not quite true. purple martins, swallows (most swallows, I'll get to that in a minute), sparrows, starlings and other insectivore birds have a hard time catching insects as small as mosquitoes. Also, mosquitoes are a pretty small meal, and they don't swarm. Look at it this way, would you bother growing and eating corn if each stalk only produced 1 or 2 kernels? But the biggest problem with attracting birds to your house is that birds are one of most mosquitos' favorite foods. Add to this the fact that West Nile virus needs birds as a primary carrier has actually gotten me to think seriously about taking the gourds out of my trees. (oh, come now, don't tell me you've never made a bird house from a gourd before?)

Bats have the same problem, although to a lesser extent. North American bats, for the most part, eat more mosquitoes than all but one bird species on the same continent (the tree swallow, Tachycineta bicolor, a difficult bird to keep around since house swallows and starlings are very aggressive toward them. If you want to attract them, try planting some bayberry). But when compared to the amount of other insects bats eat, bats don't really put much of a dent in the mosquito population due to the same reasons birds don't; mosquitoes are small, and don't swarm. Bats though, unlike most insectivore birds, are better equipped to hunt in the low light conditions during which mosquitoes are most active.

Side note: Bats are great at controlling other insect populations though. Even a small bat house nearby will greatly reduce your number of June bugs, moths, stinkbugs, boxelders, and the like. Plus, unlike birds, bats don't usually feed on dragonflies since dragonflies stay so low to the ground. plus, the big bonus for a gardener; guano. For a great site on bats and bat houses check out this link:

So if birds and bats aren't the mosquito hunters they are touted to be, then what?

Toads and frogs.

Both eat hundreds and hundreds of adult mosquitoes every day. Both enjoy the same sort of wet environments that mosquitoes enjoy, and tadpoles eat mosquito larvae. In fact, the only real problem with toads and frogs is that they also eat dragonflies. If you already have a pond or stream (natural or artificial) then you probably already have quite a few toads and frogs. If you haven't seen any, you can import some. Just find a nearby ditch or pond in late spring and capture some tadpoles. You'll want to also bring enough water from their original environment so you don't have to add chlorinated water while the tadpoles develop. My personal technique is one from childhood. Take a bucket and a plastic cup down to the stream edge. Then, stir the water along the edges slightly so that the tadpoles try to swim away. Scoop them up; water and all, with your cup and then gentle pour them into the bucket. Keep scooping water and tadpoles until the bucket is full. If you're lucky, you'll get dragonfly larvae too. Once the tadpoles mature, keeping them around is as easy as providing plenty of things to hide under during the day, and a plentiful water supply that is accessible to them. For my yard, I dug some small holes in the dirt and then placed landscaping rock over the shallow holes. As for the water, my shallow cattail garden must be pretty comfortable, because I have plenty of these guys around. Just watch out when you're mowing the lawn.

Finally, did I mention dragonflies? They are near the ultimate mosquito killer. An adult dragonfly will eat twice the number of mosquitoes that a frog or toad will. Problem is, while they are truly mosquito hunting machines, they require the exact same habitat that mosquitoes thrive in. Since mosquitoes are a major part of the dragonfly's diet from the day the dragonflies hatch from their eggs to the day they die, even if you could develop a large enough dragonfly population to make a significant dent in your mosquito population, once the mosquitoes are gone, the dragonflies will move on.

Which brings us to Deterrent.

Our heroic efforts have gone to naught! We are beset on all sides by buzzing wings that call out for blood! Oh cruel fate that we should be thus plagued for no greater sin than sweating and breathing outward!

Fear not.

We have been granted mint, basil, sage, and greatest of all our protectors; catnip.

all kidding aside, catnip has been proven in lab studies to be just as effective as DEET but not nearly as long lasting. If that's not enough, it's pretty (well, to me anyway) and there are quite a few other plants in the Nepeta family that have shown promise as mosquito deterrents. I have quite a bit of Ground Ivy (N. hederacea) along paths and around landscaping rocks and it is beautiful stuff. I've planted stands of catnip (N. Cataria) mauve catmint (N. Faassenii) basil red rubin (O. basilicum 'Purpurascens') and may night sage ( S. nemerosas) all around the place. Using the foliage of these plants to add interest to the ever-changing collection of annuals that surround them.

While planting Nepetas, Salvias, and Ocimums will add attractive, somewhat utilitarian, plants to your ornamental landscaping. Planting them in and of themselves will not deter mosquitoes from looking around your garden for a nice meal. It is the essential plant oils that provide the repellant effect. Which means that the plant must be crushed for it to be useful as a repellant.

This is one of the reasons I like Ground Ivy (also called, Gill-over-the-ground, N. Hederacea). As a ground cover, it is often trampled, and it actually holds up to light traffic, especially at it's edges. The other plants will require having the oil extracted and then applied to the skin frequently. The solution I've come up with is to crush the green plant leaves and stems with a garlic press and then boil them in a covered pot. It's important to cover the pot since, if you didn't, the essential oils of the plant would be carried away with the steam. I boil the "soup" for 5 to 10 minutes, and then bring it down to a simmer for 30 minutes. Afterwards, I let it cool down; pour it into an old gallon milk jug (actually, used to contain orange juice, If you use a milk jug that once had milk in it, you'll want to make sure it's washed out very well). I store the jug in the refrigerator, where it will keep for about a week, maybe two. When I want to use the concoction, I put it in one of those cheap mister bottles and carry the bottle with me. Before spraying, it's important to shake the bottle vigorously in order to mix the oil and water well. Then, every 5 to 10 minutes, or when I'm feeling hot, I spritz myself with a cool, fragrant mist.

Again, I've found this to really work pretty well, but it requires having to reapply it fairly often. If I went about it the hard way, extracting the essential oils, mixing with another oil base, such as olive oil, and applied it that way, it would probably last longer and require less reapplication. But my way gives me a nice refresher and mixing up a gallon of the stuff takes about as much time as making spaghetti.

Should you like to try the hard way there is plenty of information on the web. Here's a good one from an odd place:

I should point out that these plants all do pretty much what DEET does, just to much less of a degree. Mosquitoes use chemical, visual, and thermal cues to locate us. DEET and these plants work by blocking the mosquito's chemical receptors for carbon dioxide and lactic acid, two of the primary substances released by our bodies that attract mosquitoes.

Of course, DEET is a little different from the botanicals I mention. For one, it actually will keep you from getting bitten should a mosquito accidentally land on your skin. For some reason, mosquitoes will not bite skin that has been treated with DEET, even though they will gladly bite skin just centimeters away that has no DEET on it. The botanicals, on the other hand, offer nearly no protection should a mosquito still happen to find you. Of course, the other (for me, more important) difference is that DEET would make me very sick if I should be foolish enough to make tea with it. Catnip makes a fine tea.

As for the old stand-bys:

citrus, eucalyptus, citronella, dryer sheets, skin-so-soft, menthol, and other strong scented stuff, DOES work, but in a very limited way. If you've ever tried to cover up the smell of your cat's liter box by lighting incense you understand why. These materials all have very strong scents that overpower the subtle scents mosquitoes use to find us, but once the applied scent evaporates or is dispersed the underlying scent is still there and the mosquito hones in on it. To simplify, Citronella, and the like, covers up your scent. Catnip and her family and friends, actually keep the mosquito's nose from working.

Of course, mosquito nets, tents, and the like all work as long as no mosquitoes are allowed to get in, and as long as the netting isn't in direct contact with your skin.

My favorite way of repelling mosquitoes though is especially good on still, muggy, breezeless summer nights.

An oscillating fan.

Mosquitoes are light and not very strong fliers, any strong breeze will keep them from flying. Also a strong breeze disperses the chemical attractants your body produces making it even more difficult for the petite pests to find you.

Finally, as my grandmother would say, an ounce of prevention is worth a pound of cure, so be aware of what a mosquito looks for when looking for a picnic spot:

Dark Clothing

Many mosquitoes use vision to locate hosts from a distance. Dark clothes and foliage are initial attractants. Although florescent clothing seems to attract some mosquitoes as well. Good choices are white (of course), pink, pastels, sky blue, khaki, and pale yellow. If you wear Black, Navy Blue, or Burgundy, it's like hanging out a sign that reads, "Eat at Joe's"

Carbon Dioxide

You give off more carbon dioxide when you are hot or have been exercising. Of course, you could stop breathing (I won't recommend it) you can also distract the mosquitoes by putting a block of dry ice far away from the party. Also remember, fires, candles, and any other sort of combustion also emit CO2

Lactic Acid

You release more lactic acid when you have been exercising or after eating certain foods (e.g., salty foods, high-potassium foods, thus the reason eating bananas attracts mosquitoes). This is as easy as getting it off of you. Change clothes, take a shower before going back out. Use unscented baby wipes to remove the sweat and dirt trapping the lactic acid on your skin.

Sweet, Floral or Fruity Fragrances

Perfumes, hair products, many scented sunscreens and skin lotions, and a host of other outdoor products use scents that actually attract mosquitoes. Best advice; use unscented beauty and hygiene products if you plan on being outside at night.

Skin Temperature

The exact temperature depends on the type of mosquito. Not a lot you can do about this, although taking a dip in the pool or relaxing in front of a fan would help. (not to mention feel good)


Mosquitoes are attracted by perspiration because of the chemicals it contains and also because it increases the humidity around your body. Keep a towel around. Dry yourself often. Wear clothing that breathes and helps your sweat evaporate faster.

Well, that's it. It's more than I actually intended to write, but if it helps anyone out there who suffers from mosquitoes as much as I do, it was worth the time to write.

Comments (20)

  • bigpaulie1972
    16 years ago
    last modified: 7 years ago

    excellent post! Thanks! What species of Eucalyptus are the best to plant for a passive repellent? I live in florida where the state bird is the mosquito. I planned on getting the mosquito magnets in the spring, but any other help I can give them will be a good idea.

  • Fetters
    Original Author
    16 years ago
    last modified: 7 years ago

    I would have to say Lemon Eucalyptus (Eucalyptus maculata citriodon) is by far your best choice. It's advantage is that it has large folliage glands called trichomes. Most plants have trichomes. It's these glands that release the strong scents associated with such folliage plants such as mint, catnip, most herbs and, of course, Eucalyptus. The larger and more densely packed the trichomes on a plant's folliage, the stronger the scent of the plant. What makes Lemon Eucalyptus special (along with Eucalyptus in general) is that it has large trichomes with large openings. This means that the plant has a very strong odor, without having to be greatly disturbed or, like most herbs, crushed.

    A caveat about Eucalyptus. As I mentioned before, Eucalyptus works by covering the scents of mosquito attractants. This confuses and irritates mosquitoes and will hopefully deter them from the vicinity of the tree. But, these plants have a VERY strong scent. So I would see if you can find someone (maybe a nursery) who has a mature, healthy plant, so you can sample the fragrance and decide if you can live with having it in your yard.

    Also, from what I've found, Eucalyptus in not an invasive plant, but I would avoid the Tasmainian Blue Gum (Eucalyptus globulus). It's trichomes are even larger and more dense than Lemon Eucalyptus (even though they produce a less concentrated citronellal oil than other species of Eucalyptus) but since the flowers are too deep for native nectar-eating birds, the birds will often suffocate while trying to feed from this plant.

    hope that helps.

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  • tufaj
    16 years ago
    last modified: 7 years ago

    That was an interesting post.

    How toxic do you find that Bt is to butterflies? This was one of the concerns of the Bt genetically modified corn that was being planted. Tests by Cornell University showed that the pollen was toxic to Monarch butterflies.


  • rhizo_1 (North AL) zone 7
    16 years ago
    last modified: 7 years ago

    Jean, completely different Bt strains. Bt-israelensis is what works against mosquitoes and other Diptera larvae. Bt-kurstaki is the strain that is effective against caterpillars. Read the directions carefully before purchasing Bt to make sure that you are buying the bacterial inoculant you need.

  • Fetters
    Original Author
    16 years ago
    last modified: 7 years ago

    As Dorie said, Only the kurstaki strain of Bt will kill catapillars.

    Also Jean, I think the cornell study your refering to was testing a genetically engineered corn where they introduced the BTk delta-endtoxin gene into the corn's genes so the corn itself would create the delta-endtoxin. Thus eliminating the cost and problems associated with application. It also ment that the delta-endtoxin is present in the corn's pollen, which could then be blown onto milkweed leaves where monarch catipillars would then consume it.
    The link I attached to this post has a very good FAQ on the subject.

    Here is a link that might be useful: USDA article on Bt corn and it's effects on Monarch Butterflies

  • kris
    16 years ago
    last modified: 7 years ago

    Wow very thorough.

    Just a few comments if you would like them :) and a question

    1.) You might stress that people use Bt not just because it is less toxic but because it is selective and only attacks a certain category of insects without harming beneficials. You brushed on this but this is the major reason I use it.

    2.) Bats are major rabies carriers-that's a significant con.

    3.) You might try (since your the guinney pig :)) extracting the essential oils of the herbs into ethanol (everclear or high proof vodka) or into rubbing alcohol. I haven't done it, but those solvents are more 'oil like' than water (with rubbing alcohol more so than ethanol) so they might extract higher quantities of the oil and they are nice for sprays, ie they evaporate quickly on the skin and feel good. When heating those solvents ethanol boils at like 60C and rubbing alcohol lower 80C (if its a mixture with water, like the volatile oils you mentioned, both solvents will boil before water so a lid would be needed). A double boiler would be safer probably, just watch out cause they are both flamable. Though it is possible you would extract something from the herb that you wouldn't want on your skin but I don't now.

    Do you know anything about the stability of Bt? I know its not so stable to light (so I spray at night) but is a solution made up stable if its in the dark or once you dilute the bacteria do they die?

  • honu
    16 years ago
    last modified: 7 years ago

    Thank you very much for sharing your research! I have a terrible mosquito problem in my yard year round, and appreciate all the information.

    "Also in the dry suspension category is a product called mosquito bits. Like dunks but granule size."

    I compared the labels of dunks and bits -- and am curious about the scary hazard to human health warning on the BITS, to consult a poison control center if it gets on your skin (so do you have to wear gloves and should not sprinkle near edible veggies?), etc., while the dunks did not have such a warning. Also, the info indicates the bits are quick acting, whereas the dunks are a longer term solution. If they are both BT based, what actually is the difference, and why are the bits faster acting, and why would the bits have such a severe warning that the dunks do not?

    I love the IDEA of natural controls like eucalyptus trees and toads, but in my experience, they haven't worked.
    I am growing lemon eucalyptus just for that purpose, but they do not make a bit of difference as far as mosquitoes finding me. In fact, I question it's effectiveness as a general insect repellent because I keep seeing holes chomped in the leaves. But it does make my fingers smell nice when I crush the leaves.
    Also, I have tons of toads and now even some newcomer frogs in my yard, so many that I have to be careful not to step on them when walking in my yard at night. They look well fed, but just can't keep up with the plentiful bug supply in my yard... I guess that's why they are here...
    I haven't tried catnip, yet, but after reading your post, I will.

    The only thing that has made a dramatic difference is the mosquito magnet you mentioned. Like you said, it's really expensive, but it works. Not only is the purchase price high, but it's really expensive to keep refilling the propane tanks here.

  • Fetters
    Original Author
    16 years ago
    last modified: 7 years ago


    Thanks for your comments. Actually, any comments or critiques are always welcome.

    Your right about selectivity being possibly the most compelling reason for using Bti. I will be certain when I get to writing my final article that I stress that point a little more.

    As to bats as major rabies carriers. This is a myth. statistically only 1 human being in the united states dies from rabies contracted from a bat bite per year. The vast majority of rabies cases, both fatal and non-fatal, are contracted from contact with feral dogs and cats (as opposed to strays who, in general were once pets and once vacinated, feral house pets are the result of strays who have had litters in the wild) The reason for this is human contact. A person is much more likely to approach a sick or injured dog or cat, than they are to try and handle a sick or injured bat. Since rabies is primarily transmitted to humans by bite, approaching ANY sick or injured mammal puts one at possible risk for contracting rabies.
    I have had a bat-house in my backyard now for 5 years. Over that time I've found many dead bats around the base of the house, and even a few sick ones. I NEVER attempt to handle them myself. Instead, I call animal control who then collects the animal or the carcass and tests it for rabies among other things. So far, I have never had a bat test positive for rabies and my colony has between 1 to 2 dozen residents.
    For more information on this myth and other myths about bats, please visit:

    Again, I use my simple method of "souping" the herbs mostly because I'm relatively lazy. Although, if I get ambitious I will look into your alcohol suggestions :)

    as for stability of Bti. Both the bacteria and the delta-endtoxin are UV sensitive. So yes, exposure to daylight will reduce the length of time Bti is effective. As for storage, everything I've seen suggests that the prepared mixture should be storable in a dark, room-temp environment for up to a week.

    Honu, Mahalo for bring the label for the mosquito bits to my attention. I found the MSDS on both Dunks and Bits and found that neither are significantly toxic to humans. (pdf links below)

    But as you discovered the bits label does have some scary warnings about skin contact and ingestion. I wrote Summit Chemicals about this and have yet to hear back from them. But will let you know when I do.

    I'm not suprised that natural controls don't work for you! My mother is from Kaua'i and I've been back to visit my grandparents pretty often. Wish I had some advice for you that was less expensive than the Mosquito Magnet. Unfortunately, I don't think even the catnip will be enough to keep the hawaiian mosquitoes at bay.
    My grandparents have a large porch with 3 ceiling fans. I'm not sure if this alone would work, since they also have mosquito netting drapped all around the porch. I can say for certain I've never been bitten ON the porch.

    Here is a link that might be useful: The Bat Conservatory

  • Fetters
    Original Author
    16 years ago
    last modified: 7 years ago

    Here is the reply I recieved from Summit:

    The warnings that are on the package are standard warnings for certain classes of insecticides given to us by U.S. EPA. They are not product specific and are very outdated. The Mosquito Bits are a very similar product as the Mosquito Dunks. The active ingredient is Bti which is the same as the Mosquito Dunks. The Bti is coated on a corn cob base with vegetable oil. That is all that the Mosquito Bits consist of.

    Sam Ashton

  • honu
    16 years ago
    last modified: 7 years ago

    Aloha Fetters! I am so happy to meet someone who understands the special challenges we have in Hawaii!
    I'm a little disappointed, but not surprised, to hear catnip will probably not work here either... just as well, since I don't want to make my yard more attractive to cats, as a neighbor's cat already uses it as a daily toilet.

    Thank you very much for explaining the difference between dunks and bits and for researching the warning... this actually scared me away from buying the bits, but I did buy the dunks, since that package did not have as severe a warning for some reason.
    Also the info on UV sensitivity of BTI is good to know.
    Since I don't want to use DEET, the only cheaper method to work for me other than the mosquito magnet, was to apply LOTS of Repel Lemon Eucalyptus lotion, AND over that, wear long sleeved collared shirt, gloves, hat, long pants, and boots, and suffer from the heat of wearing all that in our warm climate... and sometimes even after that I'll get a bite or two right through the clothes, but without all that, I would be covered with bites in seconds.
    Thanks for sharing such excellent information!

  • mavis
    16 years ago
    last modified: 7 years ago

    Wow - that is a fantastic post.

    I would add one more caveat - it's about scooping tadpoles and transporting them. Here in the PNW, one of the most aggressive invasive species is the bullfrog that has been transported from the East by well-meaning folks. The American bullfrog eats up native frog spawn and tadpoles, other frogs even birds, snakes and other amphibians. But they really do the number on native frogs by out competing for their habitat.

    In the PNW, it is best to let the frogs come to you. If you create a pond with a gradual entry, some shade and atleast 18 inches of depth, the native treefrog(s) will likely make its way to your pond. If the pond is a natural one that dries out at some point in the season, so much the better, as bullfrogs require permanent water sources.

  • tidewaterlilly
    16 years ago
    last modified: 7 years ago

    this is going to sound silly, but if you put a few dryer sheets on your person while out in the yard the blood suckers won't bother you. I put one in each of my back pockets.It looks like I have two flags on my rear, but who cares, it works. My friend puts one under the rim of his hat. Hope this helps,lilly

  • OzOrganic
    16 years ago
    last modified: 7 years ago

    My question involves natural elimination of mosquito larvae.

    I have a small back patio and due to some questionable landlording there is a semi-permanant puddle that stretches on a concrete slab down the side of the house. There is no way to drain it, other than to push it onto my neighbors concrete slab and I don't think they would appreciate that. The puddle gets larger and smaller based on rainfall and sun, but never disappears.

    So my question is, what can I put in the water that will be toxic to the abundant mosquito larvae, but not actually a chemical. (For instance, bleach would probably be effective but then you are left with a puddle of bleach instead) I was reading about what looked to be a science fair project where orange peel was used with result. Or how about salt?


  • macbirch
    16 years ago
    last modified: 7 years ago

    Thank you Fetters. Really good post.

    Quite timely for us as DH has suggested putting in a garden pond. My first question was, "What about the mosquitoes?"

    I was intrigued by the mention of Lemon Eucalyptus. E maculata sounded somewhat familiar so I assumed we call it something else down here. I googled it and this is what I found. E maculata is known as Spotted Gum or Honey Gum (good for bees). E citriodora is known as Lemon-Scented Gum. And there is a hybrid E maculata citriodora. Recently these particular gums have been reclassified from Eucalyptus to Corymbia (useful to know in case the nurseries change the labels). I debated whether to mention the next bit. In some areas they are getting a reputation as an invasive weed. It's hard to know when such a reputation is truly warranted. (I have some birch trees, which are most definately not indigenous to my area, and I do get seedlings coming up, but after all these years my birches haven't taken over the nearby bushland. Or is that because they have no chance against the Patterson's Curse, which was once an introduced garden flower.) I suppose all I can say is do some research if you're thinking of planting one. Perhaps conditions in the areas of the US where they are grown are such that they are happy enough to grow okay but not so happy that they get out of control. And the good news is if you change your mind after you've planted one, it apparently makes really good timber.

    Hello OzOrganic. Sorry to hear about your landlord issue. Don't get me started on that subject. Hope you find a solution soon.

  • nosyrosie
    15 years ago
    last modified: 7 years ago

    I'm bumping this up to the top because it's such a thorough post on the subject.
    *Fetters, you're the bomb.

  • caroline1
    13 years ago
    last modified: 7 years ago

    I have lived in a number of states-all of which claimed that the mosquito was the state bird. I thought I had seen it all until moving to NE Arkansas - the heart of rice growning country. I lived in a very rural very swampy area surrounded by rice paddies. The skeeters there were like something out of a biblical plague from March through Oct. We appreciated the sight of dragonflies because we knew that meant they were hunting and the sound of their wings tended to scare off some. Yes, night is worse.
    One thing I learned from the locals was that mosquitos are poor fliers - a well placed fan on "High" by your front door 24/7 will kill THOUSANDS a day and keep a good percent from getting inside. Of course, they still pushed their way in through screens, etc. When we first moved there they told us, "We have 2 types of mosquitos: the kind that push their way through your screen and the kind that open the door themselves". I believe it now.
    Another thing the old timers told us: It was never bad when we used DDT.
    Anyway, hope that helps, even if a little.

  • devi75
    12 years ago
    last modified: 7 years ago

    I live in Asia. I also do a lot of research about mosquito magnet. I'm agree that this device works very well if you install it properly. However, I can't find any information whether or not it can really kill asian tiger mosquito. Hope you can help me here. Thanks.

    Here is a link that might be useful: The Pros and Cons About Mosquito Magnet

  • mustard_seeds
    12 years ago
    last modified: 7 years ago

    I am bumping this after getting eaten alive yesterday - we have had so much rain the mosquitos are in heaven. And I am going to try making some extract from my catmint leaves, thanks OP for these tips.

  • Fetters
    Original Author
    12 years ago
    last modified: 7 years ago

    Thanks for the bump mustard_seeds. I had actually forgotten writing that post. In the end the article I wrote ended up being significantly shorter and (imho) much less informative than what I've presented here. Thanks to everyone for the compliments and input.

  • dsdesignsart_verizon_net
    11 years ago
    last modified: 7 years ago

    What about Garlic? I have heard that Mosquito Barrier - a Garlic concetrate works well. Anyone tried that?