Just when I think I’ve seen everything…I discover there is an app for your iPhone that claims to  repel mosquitoes with high frequency sound:

“Have you ever been camping and you were worried about those mosquitos [sic] outside near your camp light? Wondering how soon it will be before they attack you in your sleep? Well, today’s the day that the “AntiMosquito” app will save your life! It produces ultrasonic-sounds, ranging from 16 KHz to 20 KHz, at frequencies that are way too high for us — humans — to hear!

I personally tried this app when I was on vacation and it worked perfectly! There is one downside to this app, but it’s not really the developer’s fault but rather Mother Nature’s: other animals can here [sic] these sounds and could make them go crazy. The only other problem is that a few people stated that some mosquitoes (again Mother Nature) aren’t affected by these sounds. So a “patch” would be appreciated to cover these specific mosquitoes.”

And, gentle readers, I believe you know what I’m going to say about this:

BULL.

SHIT.

I have covered, in detail, the utter failure of any ultrasound device to repel anything besides common sense.
And, perhaps, money is also repelled out of your wallet.

The developers of this app have clearly gone to a great deal of time and trouble to make this thing look like it’s doing something. And, for all I know, if the iPhone is *capable* of producing sound in these frequencies–which is doubtful–it may really be doing so.  However, that doesn’t change the fact that ultrasound has been shown again and again and again over the last 20 years to utterly FAIL at repelling mozzies.

I would like to direct your attention to this excellent publication by Purdue University’s Extension service.

Whatever Works For You: “New Magical Remedies for Pest Eradication”

I can provide that note in a PDF form, if you would like to print it out and have it handy to give to credulous folks that want to tell you that this app does anything.

I have gone back and forth on what to write on this day.

On the one hand, this is an opportunity to reflect on the tremendous progress we’ve made so far. On the other hand…the UN set 2010 as the date for uniform malaria coverage.

There’s 614 days left until the day set as the target.  The plan is that by 2010:

• 80% of people at risk from malaria are using locally appropriate vector control methods such as long-lasting insecticidal nets (LLins), indoor residual spraying (irS) and, in some settings, other environmental and biological measures;
• 80% of malaria patients are diagnosed and treated with effective anti-malarial
• treatments;
• in areas of high transmission, 100% of pregnant women receive intermittent preventive treatment (iPT);
• the global malaria burden is reduced by 50% of the 2000 levels: ~175-250M cases annually and less than 500,000 deaths annually from malaria.

This graph from the Global Malaria Plan shows the projected effects of these interventions on different timelines.  Acting quickly will save lives.

What can we, as individuals in the US, do?

Nothing but Nets is one way to contribute.  Let major pharmaceutical corporations know you applaud (and expect!) their efforts to lower pricing on malarial drugs.  Lastly, let your legislators know you support funding for malaria research and aid.

That last one is hard–right now things are pretty tight in the US for a lot of people. Personally, I may actually have to abandon our house and let it go into foreclosure, if we can’t sell it soon.

But I’m still so, so privileged to live in a place with clean water and electricity on demand and little threat of infectious disease (relatively).  Don’t forget that even now, as financial times are hard, we still are pretty darn lucky compared to our brothers and sisters in Africa, Asia, and South America struggling with malaria.

And now…back to World Malaria Day [Week] here at the Bug Blog.  This has to be one of the most charming rap songs ever–a group of Atlanta kids do a rap song for Nothing but Nets.

I am very curious about the curriculum in which these students were introduced to malaria and Nothing but Nets. I can imagine some things you might do, but it’s a pretty complex topic. Anyone know?

Welcome to the second day of World Malaria Day [week] at the Bug Blog! I’ve talked several times about the way in which different mosquitoes respond differently to pesticides for malarial control, but here’s a new twist.

In a recent study to compare different species of mosquito in their ability to be a malarial vector, there were very large differences!

As a review– a disease vector is an organism that does not cause disease itself, but transmits an infection by transporting pathogens from one host to another. The malarial parasite is alive inside the mosquito, although they don’t get malaria–but they can give it to us, the host. In this research, different mosquitoes were compared in their abilities to serve as a vector for malaria.

One of the claims frequently made by the “DDT will solve everything” crowd is that just spraying enough DDT will kill all the malarial mosquitoes.  This ignores that mosquitoes vary widely from population to population, and species to species, in their ability to resist DDT.  They aren’t all the same, and there is no one size-fits-all control method.

The research I discussed yesterday is another good example of the variability problem–predicting malaria using weather and other environmental data in different areas of Africa required different solutions.

In this experiment, you can get a sense of another layer of difficulty in controlling malaria. The experiments looked at two different strains of malarial parasite (Thai and Korean), and 3 different mosquito species.  That’s a lot of potential variation!

What did they find out?

I won’t go into the specifics–you can read the paper if you want to see technical words like “sporogony”–but basically, not all of the mosquito species were able to support the malarial parasites’ life cycle.  (BTW, this diagram is probably the single greatest cause of drinking in invertebrate zoology students. The names! The stages! Ugh!)

Infecting a mosquito with the malarial parasite isn’t enough–the parasite has to change, migrate out of the gut of the mosquito, and into its salivary glands.  Not all mosquito bodies are equally friendly to this process–there were large differences between the 3 mosquitoes tested in this experiment.

Hopefully this gives you a sense of the complex layers of difficulty surrounding malarial control–in addition to the environmental variability  from location to location discussed yesterday, and variation in pesticide resistance which I’ve discussed before, there are also large genetic differences within mosquito species, mosquito populations, and malarial parasites. It’s a spaghetti tangle of variables, many of which we have no control over.

This is why there is no easy solution to malaria, and why after centuries, we are only now beginning to make progress.

But we are making progress! Just not as fast as we’d like.

Citation:
Joshi, D., Choochote, W., Park, M., Kim, J., Kim, T., Suwonkerd, W., & Min, G. (2009). The susceptibility of Anopheles lesteri to infection with Korean strain of Plasmodium vivax Malaria Journal, 8 (1) DOI: 10.1186/1475-2875-8-42

So much new and interesting malaria research has been coming out lately, I thought I’d post some as we approach World Malaria Day.  Here’s an assortment of research that shows how knowledge of basic mosquito biology and ecology can help control malaria.

First, a neat study that combines entomology and hydrogeology in Niger:

“efforts to control environmental factors –such as working to eliminate the low spots where pools of water collect during the rainy season, or applying locally grown plant materials to limit the growth of mosquitoes — can have a dramatic effect on controlling malaria’s spread. And unlike importing expensive medicines, such an approach can rely on local efforts as simple as having people with shovels fill in the low spots in the terrain.”

Sometimes the simplest tools are the best!  Because mosquitoes need a week or so of standing water to reach maturity (the bitey stage), getting rid of the water, or helping it drain faster, is a locally-controlled way to stop the mozzies.  You can read more about this work (with lovely photos and diagrams!) on their laboratory pages.

Unfortunately, that may not work everywhere–in Gambia, the production of malaria-transmitting mosquitoes is too widespread (and unpredictable) during the rainy season for prevention. In fact, rice fields seem to be the main locations of mosquito breeding–so cultural control of mosquitoes would devastate the local economy.

Fillinger, U., Sombroek, H., Majambere, S., van Loon, E., Takken, W., & Lindsay, S. (2009). Identifying the most productive breeding sites for malaria mosquitoes in The Gambia Malaria Journal, 8 (1) DOI: 10.1186/1475-2875-8-62

Other authors used knowledge of mosquito life cycle, in combination with remote sensing data for vegetation and rainfall, to try to predict when malaria would be a problem in Sudan.  Modeling to predict outbreaks has been done for centuries, but now we have new tools that allow new variables to be added in.

Gaudart, J., Toure, O., Dessay, N., Dicko, A., Ranque, S., Forest, L., Demongeot, J., & Doumbo, O. (2009). Modelling malaria incidence with environmental dependency in a locality of Sudanese savannah area, Mali Malaria Journal, 8 (1) DOI: 10.1186/1475-2875-8-61

That’s a quick look at some environmental research on malaria–later this week I’ll look at some new research on bednets.

Just a little reminder that WMD is April 25th, 2009.

I’ll be covering some new and cool malaria research over the next week or two as we count up to  World Malaria Day. As a reminder, you can donate to Nothing But Nets online anytime.

Here’s a fascinating new bit of research that creatively gets mosquitoes to kill themselves:

Malaria prevention with a plastic flower:

“The small device is essentially an artificial flower, made out of the same type of plastic used for football helmets. Mosquitoes are drawn to the ProVector by a four-color decal (different mosquito species are attracted to different colors).

The insect feeds on an artificial nectar through a metal screen with openings big enough for only a mosquito’s mouth parts to fit through. Kollars’ work in developing the ProVector Bt formula is unique in that it is the first time anyone has been able to get mature mosquitoes to ingest and die from Bacillus thurengiensis (Bt), a safe biopesticide.”

I haven’t been able to find an actual citation for testing of this device– can anyone send that to me?  It seems like CO2 may also be involved in the attraction.  There are some news items about DOD testing, which might not be out in press yet.

Hmm. I am extremely skeptical about the success of this project.  From WSJ:

A quarter-century ago, American rocket scientists proposed the “Star Wars” defense system to knock Soviet missiles from the skies with laser beams. Some of the same scientists are now aiming their lasers at another airborne threat: the mosquito.

In a lab in this Seattle suburb, researchers in long white coats recently stood watching a small glass box of bugs. Every few seconds, a contraption 100 feet away shot a beam that hit the buzzing mosquitoes, one by one, with a spot of red light.

The insects survived this particular test, which used a non-lethal laser. But if these researchers have their way, the Cold War missile-defense strategy will be reborn as a WMD: Weapon of Mosquito Destruction…….

“We like to think back then we made some contribution to the ending of the Cold War” with the Star Wars program, Dr. Kare says. “Now we’re just trying to make a dent in a war that’s actually gone on a lot longer and claimed a lot more lives.”

The scientists envision their technology might one day be used to draw a laser barrier around a house or village that could kill or blind the bugs. Or, laser-equipped drone aircraft could track bugs by radar, sweeping the sky with death-dealing photons.

This story has been picked up and run all over.  The scientists named in it do seem to be legit, and Intellectual Ventures, LLC is a real company. But…

This really seems problematic. Especially since all that was shown was a video of a mosquito bursting into flame.  Was it real? Who knows.

None of the scientists named in this story seem to be entomologists, although it does say “Dr. Wood, Dr. Kare and another Star Wars scientist teamed with an entomologist with a Ph.D in mosquito behavior and other experts.” Anyone know who that ento is?

The scientists interviewed say they plan to put lasers in villages in Africa to protect them from malarial mosquitoes. (Presumably they will also invent a sustainable power supply to run it.)  Some stories also mention hand-held personal versions.  The current (non-killing) version in the demo requires a desktop computer to run it.

Would this be completely freakin’ awesome if it’s real?
Yes.
Good luck to them, and I hope it works.

However, I think this will be about as successful as the first Star Wars system. And I think the primary purchase of this news story is to drum up capital for Intellectual Ventures.

Looks like there could be a new repellent compound to choose from on your shelves soon!

The compound, isolongifolenone, is made from a tree with the charming name of Bastard Bulletwood.  From the abstract:

We show that (Ð)-isolongifolenone deters the biting of the mosquitoes Aedes aegypti (L.) and Anopheles stephensi Liston more effectively than the widely used synthetic chemical repellent…(DEET), in laboratory bioassays. The compound also repelled blacklegged ticks… and lone star ticks,  as effectively as DEET.
Isolongifolenone is easily synthesized from inexpensive turpentine oil feedstock. We are therefore confident that the compound has significant potential as an inexpensive and safe repellent for protection of large human populations against blood-feeding arthropods.

Their tests were done in the lab, so I want to see some actual biting data with humans to verify these results.

It would be nice to have a choice other than DEET, since while DEET’s relatively safe, it is known to melt your pantyhose and stain fabrics.  (Yeah. I know. Bug Girl is not known for pantyhose wearing. But sometimes I have to, and it’s a drag when your legs are covered in both blood from smacked mozzies and stifling nylon.)

Also, not every mosquito species tested reacted the same way–some were more repelled than others. This is also true of DEET, so isn’t surprising.  The doses of active ingredient are similar to DEET, so unlike Picaridin, you shouldn’t have to apply extra doses of lotion.

Very (cautiously) exciting news!

The full citation:

AIJUN ZHANG, JEROME A. KLUN, SHIFA WANG, JOHN F. CARROLL, MUSTAPHA DEBBOUN (2009). Isolongifolenone: A Novel Sesquiterpene Repellent of Ticks and Mosquitoes Journal of Medical Entomology, 46 (1), 100-106 DOI: 10.1603/033.046.0113

In an interesting TED talk, Bill Gates releases mosquitoes into a crowd.  An excerpt:

Sadly, it only takes a few comments on the TED page until the “bring back DDT” drivel appears.  Sigh.

If you actually watch the complete talk, you see that Malaria was  NEVER eradicated in the equatorial areas, with or without DDT.  As I have said many, many times, malaria is a complicated problem, and no single chemical will be the solution.

I am not a fan of Microsoft, but I give Gates big props for trying to do something constructive with his money.  Bill also talks about what makes good teachers…good.  Very interesting.

UNHCR (United Nations High Commission for Refugees) has asked bloggers to give this campaign by Nothing But Nets some promotion.  Unfortunately, the majority of displaced people in the world live in malarial areas, and malaria is the greatest causes of death in refuge camps.

This fall, Nothing But Nets will work closely with UNHCR to send urgently-needed bed nets to more than 630,000 refugees in four countries where the threat is greatest. 

Looking for a way to give a gift this holiday season that has some meaning?
How about some bed nets?

Here’s a video that describes some of the dire conditions:

You can read more about the 4 countries that are being targeted in this campaign here:

• Uganda
• Eastern Sudan
• Kenya
• Tanzania