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[tvoivozhd <tvoivozd AT infionline.net>]

Lynda wrote:

> The fact is that IPM works.  IPM creates jobs.  Of course, there aren't big
> bucks in IPM for the big $$ companies.  Here's the other side of the
> argument over DDT:
>
> DDT A PANACEA FOR WEST NILE?
>
> THANK GOODNESS HEALTH AUTHORITIES HAVE MORE SENSE
>
> Jim Bull
>
> Detroit News columnist Thomas Bray laments that DDT is not being considered
> for use in the fight to control the spread of West Nile virus (Still in
> Denial about West Nile, 5-18-03). Bray asserts that DDT would be the most
> effective weapon to use to combat West Nile. He quotes an EPA hearing
> examiner as saying that DDT is safe, not carcinogenic, not mutagenic, nor
> teratogenic to humans. He goes on to report that the same examiner stated
> that DDT does not harm wildlife if used properly. On that basis he concludes
> that the ban on use of DDT is unwarranted and has doomed people, especially
> children, to die from malaria.
>
> Although DDT may not alter the genetic structure of an organism, it
> certainly has plenty of toxic effects. The US EPA "Persistent
> Bioaccumulative and Toxic Chemical Program" reports that DDT is a probable
> human carcinogen, damages the liver, can cause liver cancer, temporarily
> damages the nervous system, reduces reproductive success, and damages the
> reproductive system. In Israel, breast cancer rates decreased dramatically
> after DDT was banned from use on dairy farms. One reason DDT effects the
> reproductive success of organisms is that it is an endocrine disruptor which
> mimics estrogen. This can result in lower fertility in human males. In some
> species of fish it can even change their gender. It certainly can disrupt
> courtship and may make mating impossible in many species.
>
> Because of DDT's affinity for fat, it is readily excreted in cow and human
> milk, which is why the ban in Israel had such a dramatic effect. Since DDT
> resists being metabolized, it is stored in the fatty tissue of animals and
> accumulates over time. This effect is compounded in predators that eat lots
> of prey species with DDT present in their bodies. While DDT can outright
> kill some fish that have eaten too many insects laden with it, other fish
> live to pass on their accumulation to predators, including humans. Although
> it was banned in 1972, over thirty years later there are still fish
> consumption advisories for DDT in the Great Lakes and many other watersheds.
>
> In predatory birds, DDT did its damage in another way--it prevented
> sufficient production of calcium carbonate in the eggshell making process.
> The result was eggshells so thin that they broke when the adult female
> attempted to incubate them, thus many fewer young were hatched. The Bald
> Eagle, the Peregrine Falcon and many other birds were on the brink of
> extinction until DDT was banned. Banning DDT saved our national symbol.
>
> And not just large birds were affected. Many insect and worm-eating birds
> succumbed to the effects of DDT's bioaccumulation. As a child growing up in
> the 1960s, I remember seeing American Robins convulsing in severe DDT
> tremors before they died. We sent more than one carcass to ornithologist
> Walter P. Nickell (and one time DAS president) at the Cranbrook Institute of
> Science so he could forward them to Michigan State University for analysis.
> It was not a pretty sight to see. Nickell and George Wallace at M.S.U.
> supplied this kind of data to Rachel Carson as she researched her book,
> Silent Spring.
>
> A few other traits of DDT should cause concern. It takes fifteen years or
> more to break down in the environment (which is why we still have fish
> advisories warning about DDT) and it can be absorbed by some plants, which
> means that a vegetarian diet will not save you from its toxic effects.
>
> Maybe a certain amount of DDT can be consumed without killing the organism,
> but this does not mean the substance has "no deleterious effects on wildlife
> if used properly." There is no way to use DDT that will prevent
> bioaccumulation, persistence in the environment or absorption by plants.
> Delayed toxic effects are still toxic nonetheless.
>
> Would DDT have prevented the spread of malaria and would it be the best tool
> to use to combat West Nile? Probably not. There is one other fact about DDT
> and most other pesticides that needs to be told: insects develop resistance
> to pesticides. The few insects that do not succumb to the pesticide survive
> to reproduce and spread their genetic resistance. In 1997, the National
> Research Council reported 4,000 examples of resistance to pesticides in 500
> species of insects. In many cases the resistant insect population grows to
> levels that surpass what they were when spaying began. Before DDT was
> banned, this resistance was already becoming evident.
>
> What should we do? Precisely what most health organizations and communities
> are doing, using Integrated Pest Management (IPM). In IPM the ecology of the
> insect is studied, and a variety of measures are taken to control the
> infestation based on that information. A chemical or biological pesticide is
> used only as a last resort, and then only if it can be shown to be effective
> and that the benefits outweigh the risks.
>
> While we are justifiably concerned about West Nile, its human victims and
> the sporadic mortality of crows and other birds, it is not a serious health
> threat for most people. Birds are the primary hosts, not humans. Less than 1
> in 150 people bitten by infected mosquitoes get any symptoms of the disease,
> and most of those do not develop the brain infection known as encephalitis.
> No more than 10% of those who develop encephalitis die and most of those
> cases have been elderly people whose other health problems make them more
> susceptible. Flu, asthma and respiratory diseases each kill more people per
> day than the total number killed by West Nile in the two worst months of the
> "epidemic." West Nile is scary because it is new to us. We need to have a
> healthy respect for it, but not the panic fomented by sensational media
> reports. A sense of perspective is important when dealing with any serious
> problem.
>
> Eliminating habitat for larval mosquitoes in back yards, including old
> tires, pet water bowls, and other containers with still water will make it
> impossible for mosquitoes to complete their metamorphosis to biting adults.
> Using mosquito repellents, wearing long sleeve shirts and long pants, and
> reducing activities at dawn or dusk when mosquitoes are most active have
> been shown to significantly reduce mosquito bites.. Spraying pesticides, on
> the other hand, reduces the adult mosquito population only temporarily, as
> populations recover quickly and pesticide resistance emerges. Studies have
> shown that spraying distracts the public, lulls them into a sense of safety
> and deters them from implementing the very factors that could prevent
> mosquito contact in the first place. And, what Bray did not mention is that
> DDT and other pesticides do not differentiate between good insects and
> pests. Monarch butterflies and the economically important honeybee could be
> affected as well. If pesticides are to be used in some cases, after other
> IPM methods have been tried, the larvicidal bacteria that come in pellet
> form are the best choice. Even that biological control method may have some
> risks, despite claims that it is safe and is specific to only mosquitoes.
> Nobody knows for sure that this bacterium will not infect beneficial insects
> or other organisms. But it is far safer than chemical pesticides. And of the
> chemical pesticides, DDT would be one of the worst to consider. Thank
> goodness it is no longer an option in this country.
>
> There is also a problem with Bray's assertion that the ban on DDT is to
> blame for the continued high rates of malaria worldwide--most of the
> developing world still uses DDT, and much of it is imported from U.S.
> manufacturers. IPM is not only safer, it is the most effective approach to
> combating insect or any other pests, animal or plant. Maybe if the countries
> that continue to rely so heavily on DDT tried IPM, the numbers of malaria
> victims would finally start to decrease.
>
> ----- Original Message -----
> From: Gene GeRue <genegerue AT ruralize.com>
> To: <homestead AT lists.ibiblio.org>
> Sent: Saturday, January 08, 2005 8:49 AM
> Subject: [Homestead] Rethinking DDT--or should we?
>
>
>  
>
> > This is a sobering article. Along with others we have recently read, it
> > points out that malaria kills many times more people than the recent
> > tsunami did. But--somebody give me a reality check, please--I find myself
> > wondering if such human catastrophes are not simply Nature protecting
> > herself, a way that Gaia is creating a balance from the increasing
> > destructiveness of its dominant species. I feel pretty certain that human
> > overpopulation is the biggest threat to our planetary home. Yet, not one
> >    
> of
>  
>
> > us  could look a sick child in the face and not want to help in any way
> > possible. But looking at the big picture, consider the outcome if all
> >    
> lives
>  
>
> > were saved. Am I losing my humanity?
> >    
>
>  
yvoivozhd:
http://www.millennium-debate.org/ind23may023.htm (GM mosquitos to 
replace malaria-carrying mosquitos---and to resistance to pesticides either)

Bti (Bucillus thuringiensis israelensis) which is a bacteria applied to 
cobs of corn that are thrown into standing water also used to kill 
mosquito larva.

[ Back to EurekAlert! ] Public release date: 16-Jul-2004
[ Print Article | E-mail Article | Close Window ]

Contact: Michael Bernstein
m_bernstein AT acs.org
202-872-6042
American Chemical Society
Cinnamon oil kills mosquitoes
NOTE FOR REPORTERS: The statement in our original news release 
(distributed 7-15) that cinnamon oil can "kill mosquito larvae more 
effectively than DEET" is misleading since we neglected to point out 
that DEET is most commonly used in insect repellants, not as a 
larvicide. We apologize for not making this clear. Please disregard the 
previous version of this news release and use the following version.

Cinnamon oil shows promise as a great-smelling, environmentally friendly 
pesticide, with the ability to kill mosquito larvae, according to a new 
study published in the July 14 issue of the Journal of Agricultural and 
Food Chemistry, a peer-reviewed journal of the American Chemical 
Society, the world’s largest scientific society.

The researchers also expect that cinnamon oil could be a good mosquito 
repellant, though they have not yet tested it against adult mosquitoes.

Besides being a summer nuisance, mosquitoes pose some major public 
health problems, carrying such deadly agents as malaria, yellow fever 
and West Nile virus. While conventional pesticide application is often 
effective in controlling mosquito larvae before they hatch, repeated use 
of these agents has raised serious environmental and health concerns.

"These problems have highlighted the need for new strategies for 
mosquito larval control," says Peter Shang-Tzen Chang, a professor in 
the School of Forestry and Resource Conservation at National Taiwan 
University and lead author of the paper. Scientists are increasingly 
turning to more benign natural chemicals to ward off mosquitoes and 
other pests.

Chang and his coworkers tested eleven compounds in cinnamon leaf oil for 
their ability to kill emerging larvae of the yellow fever mosquito, 
Aedes aegypti. "Four compounds — cinnamaldehyde, cinnamyl acetate, 
eugenol and anethole — exhibited the strongest activity against A. 
aegypti in 24 hours of testing," Chang says.

Larvicidal activity is judged with a measurement called LC50. "The LC50 
value is the concentration that kills 50 percent of mosquito larvae in 
24 hours," Chang explains. Lower LC50 translates into higher activity, 
because it takes a lower concentration to kill larvae in the same amount 
of time. All four compounds had LC50 values of less than 50 parts per 
million (ppm), with cinnamaldehyde showing the strongest activity at an 
LC50 of 29 ppm.

Other common essential oils, such as catnip, have shown similar promise 
in fighting off mosquitoes, but this is the first time researchers have 
demonstrated cinnamon’s potential as a safe and effective pesticide, 
according to Chang.

Cinnamaldehyde is the main constituent in cinnamon leaf oil and is used 
worldwide as a food additive and flavoring agent. A formulation using 
the compound could be sprayed just like a pesticide, but without the 
potential for adverse health effects — plus the added bonus of a 
pleasant smell.

Bark oil from the Cinnamomum cassia tree is the most common source of 
cinnamaldehyde, but the tree used in this study — indigenous cinnamon, 
or Cinnamomum osmophloeum — has been of interest to researchers because 
the constituents of its leaf oil are similar to those of C. cassia bark 
oil. The leaves of C. osmophloeum, which grows in Taiwan’s natural 
hardwood forests, could be a more economical and sustainable source of 
cinnamon oil than isolating it from bark, Chang says.

Though the team only tested the oil against the yellow fever mosquito, 
cinnamon oil should prove similarly lethal to the larvae of other 
mosquito species, the researchers say. In further studies they plan to 
test cinnamon oil against other types of mosquitoes as well as different 
commercial pesticides.

"We think that cinnamon oil might also affect adult mosquitoes by acting 
as a repellant," Chang says. The researchers haven’t yet tested this 
theory, but they plan to find out in the near future.

The Council of Agriculture of the Executive Yuan, a government agency in 
Taiwan, provided support for this research.

— Jason Gorss

###

The online version of the research paper cited above was initially 
published June 10 on the journal's Web site. Journalists can arrange 
access to this site by sending an e-mail to newsroom AT acs.org or calling 
the contact person for this release.
[ Back to EurekAlert! ] [ Print Article | E-mail Article | Close Window ]

http://rds.yahoo.com/S=2766679/K=kill+malaria+mosquitos/v=2/SID=w/l=WS1/R=33/IPC=us/SHE=0/H=0/SIG=125gmv6f3/EXP=1105301071/*-http%3A//www.worldchanging.com/archives/001405.html 
(vaccine against malaria by 2010?)


iological Controls
Introduction of natural predators:
Mosquito-eating fish: Gambusia
gambusiaGambusia affinis is a natural predator on mosquito larvae. These 
fish can be stocked in ponds or ditches, if the water is deep enough. 
The nice thing about natural predators is that the mosquito larvae do 
not evolve chemical resistance. However, the Gambusia fish might out 
compete native fish in the area if its population is not kept in 
control. In the picture below, a truck stocks a body of water with fish.

Gambusia truck

Bacterial Insecticides
btiAnother option is to use bacteria to kill the larvae. Bacillus 
thuringiensis israelensis (B.t.i.) kills mosquito larvae, but does not 
harm fish, humans, or other insects except the blackfly. The larvae 
ingest the bacteria as they filter food with their mouth brushes and 
die. One limitation of B.t.i is that it has no effect on the egg and 
pupal stage, or on larvae that are ready to pupate and have stopped feeding.




Chemical Controls
Larvicides
Petroleum or special mineral oils can be sprayed on the surface of water 
where mosquitos develop. This only works well on standing water where 
the oil can produce a nice even film. The oil prevents the pupae and 
larvae from getting access to air, and as a result, they suffocate.

Adulticides
Adulticides are not usually necessary when a good larvae control program 
is in place. Early in the war on malaria in the 50's and 60's DDT was 
used to kill adult mosquitos, but in some places the vector has evolved 
resistance, and DDT is toxic to animals. Malathion and Deltamethrin are 
available instead, although they are more expensive. Biological controls 
should be used when possible, so that there is no risk of chemical 
resistance. Repellents like DEET and Permethrin can reduce the risk of 
transmission. For the debate on DDT and malaria see DDT and Insecticide 
Resistance.

Other forms of control
Mechanical forms of control include the aforementioned destruction of 
mosquito habitats (use the drop down menu for more info), wearing 
protective clothing, and putting up screen barriers. There are some 
interesting products on the market for vector control. One is the 
LarvaSonic, an acoustic larvacide. This device transmits a frequency 
into the water at the same resonance as mosquito larvae air bladders. 
The internal tissue inside the mosquito larva ruptures and it dies 
instantly.

http://www.fightingmalaria.org/news.php?ID=169&month=October+2003 (DDT 
has almost no advantage over other insecticide sprays---re-use of this 
banned chemical is is for propaganda value---its fearful damage to birds 
and amphibians is well-documented, and only too well known)

http://www.worldchanging.com/archives/000590.html (follow the 
money---who would benefit by re-introducing DDT instead of more 
environmentally-benign chemicals and simple, effective bed mosquito-netting.

Note there is not a word from any of the bring-back-DDT looneys about 
the billions of mosquitos in eavestroughs, tree-branches, creekside 
puddles, drainage ditches. The same looneys carefully avoid mention of 
the fact that, lacking spray-helicopters, homeowners aren't going to do 
a damned thing about such huge sources of the present and future 
generations of mosquitos eager to bite them anywhere outside, and to 
re-invade their house at the earliest opportunity---any time a door or 
window is opened.

Like the pyethrins, DDT has some residual effect to repel or kill 
mosquitos, but it sure as hell is not a magic bullet as the looneys 
imply. No one knows this better than I do---nor is anyone more familiar 
with the buzzing sound of mosquitos testing my DDT-sprayed bed 
mosquito-net. All I can say is that they are fewer in number after a 
room is hermetically-sealed for the night---all to return anew the next daY.

The reason I survived India and Burma was three-fold---eating Atabrine 
pills like popcorn, spraying my bed mosquito-net before I turned in, and 
spraying the interior of the thatched hut. Omit any one of these if the 
Death March is your favorite tune.

One of my favorite people, Major Rebori, came to the Air Commandos as an 
instructor in Burma, from Orde Wingate's
outfit. Due to the exigencies of jungle combat, he could not take these 
precautions when with Wingate. He was bedridden with the shivers every 
day, and died of Malaria a few months later, still in his early 30's.