Sonic-powered Mosquito Larvae Eliminator 76
Bob Vila's Hammer writes "Inventor Michael Nyberg, at the age of 15, developed the idea for a mosquito larvae eradicator after hearing about rising cases of West Nile virus. His company, Larvasonic, has developed these devices. They utilize sonic blasts at certain frequency that rupture the breathing sacs of the larvae, killing them instantly. Remarkably, it does not harm other insects and it is considered a very effective means of destroying problematic mosquito infestations."
His patent (Score:5, Informative)
Patent 6,298,011: Method for killing mosquito larvae [uspto.gov]
A short excerpt:
"Mosquito larvae have internal organs which contain various structures, including a small air bladder. All structures have acoustic resonance, especially underwater bubbles. Since larvae tissues are fragile, simply matching the acoustic resonance of the air bladder causes acute trauma and embolism resulting in death of the mosquito larvae.
Thus, referring to FIG. 1, an acoustic transducer is immersed in a body of water which is a habitat for mosquito larvae. A depth of immersion of only a few inches is required, as shown in FIG. 1. One or more transducer is preferably connected to an amplifier which in turn is connected to a signal generator for generating a resonant frequency within an octave range ranging from 16 kHz to 32 kHz. The transducer immersed in water is energized for a short period of time. The resultant acoustic resonance resonates with the air bladder of the mosquito larvae, causing it to traumatize surrounding tissue and causes the air bubble to migrate from the thorax of the mosquito through the abdomen, resulting in death to the larvae. An effective resonant frequency is from 16 kHz to 32 kHz, and less than one watt of energy is necessary to start the process. A larger signal generator would be necessary to cover a larger body of water with rapid coverage, or the unit could be effectively moved to various locations in the body of water."
Best method? You're sure? (Score:3, Informative)
Vaccines would be a good component of a defense-in-depth; the downside is that the wild reservoirs would have to be monitored and the vaccine updated (and people re-vaccinated) when it mutated.
Re:Breeding Resistance (Score:3, Informative)
I imagine it would take a lot more than just a few generations, but even then, you could just change the frequency to match the bigger/smaller air sacks. I doubt mosquitos without these air sacks are going to evolve anytime soon.
How much does ultrasonic propogate through water?
Sound of all frequencies propogates significantly better underwater than in air. From the looks of it, the device is designed to operate underwater.
Re:Breeding Resistance (Score:4, Informative)
It makes good fertilizer tho.
Re:How loud??? (Score:3, Informative)
It's also notable that the power output is supposed to be 400 W. You'd need some serious coupling to the water and a thoroughly resonant cavity, I'd think, to be able to achieve that sort of pressure (5.6 MPa) at that power level - but then, underwater acoustics are not my speciality. I did find the results of some experiments at which suggested a couple of things; the amplitude version of the dB calculation is appropriate (20Log(V2/V1)), and the potential to achieve 195 dB is not unreasonable, again assuming some increase due to resonant effects. [hearinginnovations.com]
YMMV
Re:Great Idea! Let's go for it! (Score:2, Informative)
They'll eat anything that moves and is the right size.
Re:Modern drugs (Score:3, Informative)
This is certainly a problem, and more money for malaria research would definitely help.
However, you could throw all the money in the world at the problem, and still not get a good drug as quickly as you'd like. To get a drug that is effective against a disease without also killing the host, you need to exploit differences between the host and the disease-causing organism. Malaria is caused by a eukaryotic parasite. Our cells are also eukaryotes. (Eukaryote = cell has a nucleus.) Diseases caused by eukaryotic parasites are difficult to fight, because many of the cellular mechanisms are very similar to those in the host cells. Many antibiotics (which kill bacteria, which are prokaryotes) work by disrupting things our cells don't have (like a cell wall), or by interfering with processes that are quite different in the bacteria. For instance, some antibiotics work by interfering with the protein synthesis mechanism in bacteria, which is fairly different from the protein synthesis mechanism in eukaryotes like humans.
Chloroquine was effective until the malaria parasite evolved resistance to it. All of these disease causing organisms are constantly evolving, and developing drugs that the organism can't "evolve around" only complicates the drug discovery process: you not only need to target a process that is different in the disease-causing organism than it is in the host, you also need that process to be so essential that the organism can't evolve a way to survive without it.
And by the way... we don't have an effective anti-SARS drug. Doctors were using antivirals developed to fight other diseases. There was some controversy over whether these drugs were helping or not. I can't remember how it turned out. Viruses are also difficult to combat with drugs, because they mostly use host cell resources to replicate.
I grossly oversimplified in much of this post, but you get the idea.... Yes, more money would help, but it wouldn't remove the challenging biological problems slowing drug development. It would just pay more people to try to think of ways to get around them.
Re:Too bad the mosquitos themself are part of... (Score:3, Informative)
Other detrimental species have also been introduced by ships, like rats, mice, and of course haoles like me. ;)
And then someone got the bright idea of shipping in mongoose to control the rats... but rats are nocturnal and mongoose are diurnal... whoops.
Common larvae habitats come from garbage (Score:2, Informative)
Sure, the devices will be effective with large containers of standing water like lakes and ponds. But most sources of stagnant water come from garbage [cdc.gov], old tires [cdc.gov], and even plants [cdc.gov].
As the tire is the best man-made nursery for mosquito larvae with its stagnant water and ample shade, simply throwing away used tires correctly will do more to eliminate the mosquito threat than these devices. In fact, the Asian Tiger mosquito is suspected to have arrived in the US on a shipment of used tires from Asia in 1985.
Since it appears that the devices require submersion to be effective, it's unlikely to be practical against most mosquito breeding vectors.