The Deadliest Animal in the World

http://www.gatesnotes.com/Health/Most-Lethal-Animal-Mosquito-Week?WT.mc_id=MosquitoWeek2014_SharkWeek_tw&WT.tsrc=Twitter

by beniaminmincu • 12 years ago

145 138 12 years ago

gatesnotes.com

bws99• 12 years ago

Not seeing domestic cats on this list, though I suppose they only have murderous intentions and are too fluffy to actually execute on them.

ogig9• 12 years ago

They are still in planing phase, keep vigilant.

egeozcan• 12 years ago

I guess they are busy with their plans for destroying the Earth: http://www.buzzfeed.com/smbc/cat-photo-industry

What surprised me most is learning that there is a creature which is capable of killing more humans than humans themselves.

mda• 12 years ago

Interestingly, cats are responsible for toxoplasmosis and it could be fatal in some cases. They also may carry rabies. I am pretty sure cats killed more people than sharks.

cperciva2• 12 years ago

Cats carry Toxoplasma gondii, which is estimated to cause 750 deaths each year in the US alone. Around the world it's probably many times that number -- making Felis domesticus responsible (albeit indirectly) for more deaths than lions, elephants, hippopotamuses, and crocodiles combined.

Dirlewanger• 12 years ago

Yup, which humans can pick up if they train their cat to use the same toilet as they do. Incredibly unsanitary. People and animals have separate shit receptacles for a reason.

yread• 12 years ago

It also influences human behaviour [1] which is probably why the grandparent's post is so massively downvoted ;)

It can also be deadly when it doesn't kill you "The difference in seroprevalence of toxoplasmosis in these 2 samples suggests that Toxoplasma-infected subjects have a 2.65 times higher risk of traffic accidents than Toxoplasma-free subjects"

EDIT: it also suggests an explanation: "the effects of T. gondii are best explained in evolutionary terms by the manipulation hypothesis, ie, the parasite changes the behavior of the rodent in such a way as to increase the chances of the parasite's getting into a feline and completing its life cycle."

[1] http://schizophreniabulletin.oxfordjournals.org/content/33/3...

morsch• 12 years ago

That's it, I'm getting rid of my pet cat in favor of a hippopotamus. Safety first.

cm2012• 12 years ago

The vast, vast majority of toxoplasma occurs in 3rd world countries, and living with a cat has been shown not to increase chance of catching it at all.

Wiki:

The following have been identified as being risk factors for T. gondii infection:Exposure to or consumption of raw or undercooked meat[18][39][40][41]Drinking unpasteurized goat milk[39]Contact with soil[7][40]Eating unwashed raw vegetables or fruits[18]Cleaning cat litter boxes[18]Sewage has been identified as a carriage medium for the organism.[42][43][44][45]Numerous studies have shown living in a household with a cat is not a significant risk factor for T. gondiiinfection,[18][40][46] though living with several kittens has some significance.[47]

tokenadult4• 12 years ago

You should have done more looking up about toxoplasmosis before starting this subthread. Toxoplasmosis is mostly a food-borne illness, worldwide, and especially in the United States is spread mostly by undercooked food.[1] In any event, the great majority of people infected with this parasite have no symptoms from the infection. (This is true of many infectious diseases; human beings have a well adapted immune system with a deep evolutionary history now that we and our ancestors have been living for millions of years in a world filled with other organisms. Malaria deserves special attention because the parasite is especially harmful to human beings.)

[1] http://www.cdc.gov/parasites/toxoplasmosis/epi.html

norswap• 12 years ago

They're plotting: http://theoatmeal.com/misc/frame/cat_kill

ogig9• 12 years ago

What makes mosquitoes so dangerous? Despite their innocuous-sounding name—Spanish for “little fly”—they carry devastating diseases.

Spanish for "little fly" could be "mosquita", a diminutive of "mosca" (fly). Mosquito is the spanish term for mosquito. While mosquito and mosca share the same latin origin "musca" i dont think any spanish speaker will understand mosquito as little fly.

Just a nitpick in case you were going to amaze someone with magazine learned spanish terms.

ibmthrowaway218• 12 years ago

The diminutive can be -ita or -ito depending on gender.

They may understand it as "mosquito" rather than "little fly" but that is a valid literal translation, just like "gatito" is "kitten" but the literal translation would be diminutive-of-cat -> "little cat".

ogig9• 12 years ago

Mosca has no male form, it would be a female mosca, or a male mosca. That's probably the origin of the mistake with the article. While the gatito example is ok, there is no mosco for mosca.

vibragiel4• 12 years ago

Actually, it is a diminutive for "mosco", which comes from "mosca". No Spanish speaker I know of (myself included) has trouble understanding mosquito as little fly.

ogig9• 12 years ago

Yes, mosquito it is a dimitive for "mosco", that comes from latin "musca". Sharing a latin root doesn't make them mean the same.

If you understand mosquito as "little fly", then how do you call actual mosquitos? Im from spain. I can assure you no one here will take the word mosquito for other than the blood sucker insect.

Don't say you are wrong, probably this is about diferent spanish usage since it varies from country to country and even more from continent to continent.

narag2• 12 years ago

Native here. I know mosca, mosquito, mosquita, moscón, moscarda, moscardón and even moscoso and mosquearse.

But "mosco", really?

mootothemax4• 12 years ago

It would have been quicker to tap "Mosquito etymology" into Google than it would have been to write up your incredibly petty comment:

1580s, from Spanish mosquito "little gnat," diminutive of mosca "fly,"

http://www.etymonline.com/index.php?term=mosquito

I genuinely dislike writing such harsh comments, and in this case have let the frustration of seeing this comment as the top-rated one on an otherwise discussion-worthy topic boil over.

davidw2• 12 years ago

Interestingly, Italian has 'mosca' for fly, too, but mosquitos are "zanzare", which is onomatopoeic.

ogig9• 12 years ago

What about consulting the actual, present day, normative instead of the middle age origin?

http://lema.rae.es/drae/?val=mosquito http://lema.rae.es/drae/?val=mosca

Sorry about frustrating you, and i mean it.

analreceiver2• 12 years ago

I'm a native spanish speaker from Venezuela and I can tell you that where I'm from "Mosquito" is not seen as a diminutive of "Mosca", since, like you say, the correct form to say "little fly" would be "Mosquita". So, you're right.

davidw2• 12 years ago

In a list that's supposed to point out "unexpected" killers, snakes are, interestingly, far and away the deadliest of the animals you'd actually think of when someone says "dangerous animals".

Aardwolf• 12 years ago

Wow, 50,000 snake deaths per year!

Living in Europe, I've never seen snakes except in a zoo.

How do you avoid them in a country with snakes? Can they pop up anywhere out of nowhere?

Nux• 12 years ago

You should go in the country side more, there's loads of snakes in Europe in the wild, though not Boas or Pythons.

masklinn5• 12 years ago

Even in the countryside, it's rare to see snakes unless you're actively looking for them. And the few somewhat dangerous ones (mostly the common adder) is fairly small and shy, not aggressive, and very rarely dangerous.

Synaesthesia2• 12 years ago

Really the biggest risk is if you're walking in the veld and step on one accidentally, they are not aggressive animals that seek confrontation with humans. Unfortunately they hide themselves very well and are entirely motionless when resting so it's easy to accidentally step on.

A snakebite is not usually deadly. Most deaths occur in poor parts of Africa where people do not get appropriate treatment.

atmosx2• 12 years ago

In Greece we have plenty, in the countryside and in the Islands. If you go to Ithaca for example, you'll come across many snakes in June-August if you visit the villages on the hills.

You avoid them by learning to live with them. Most snakes are afraid of human. Some are not poisonous. People who live in the specific knows what's dangerous and what's not, where they live what to do and how to react.

oska• 12 years ago

It's mostly that the snakes avoid you. Snakes don't see humans as food and so mostly get out of the way when humans approach.

In Australia, where I live, it's said that even in the suburbs there will be a snake living somewhere close by. But most people will rarely ever see a snake and most snake bites are from people being foolish, like trying to kill a cornered snake.

Only four to six Australians suffer a fatal snake bite each year, and this is with our famous collection of highly venomous snakes [1]. I understand that fatal snake bites are much more common in India though, and I guess that's from population pressure and many more Indians living a rural life.

[1] http://www.australiangeographic.com.au/topics/science-enviro...

anotherevan2• 12 years ago

The way I had it explained to me by a first aide instructor, although gram for gram of venom, Australian snakes are some of the worst, the delivery system is not as efficient.

Venomous Australian snakes generally have a groove down the outside of the tooth which the venom runs down. So when bitten a lot of venom will get soaked into the clothing, and it generally goes into the lymph node system more than into the bloodstream.

Whereas Indian snakes have a hollow tooth like a hypodermic needle which delivers the venom efficiently into the bloodstream.

benatkin• 12 years ago

Here's the Wikipedia page on it. The second table has the deaths. http://en.wikipedia.org/wiki/Epidemiology_of_snakebites

Most are close to the equator. The data confirms Aardwolf's experience.

davidiach• 12 years ago

I live in Europe too and I've seen a lot of snakes in the wilderness in my lifetime. Some of them even poisonous.

leephillips• 12 years ago

Super Pedant to the Rescue: most of them are probably good eatin' However, some of them are venomous.

Tyrannosaurs2• 12 years ago

We have adders in the UK which are poisonous, though rarely deadly (the greatest risk being to children and the elderly). They're very shy and personally I've never seen one (they are present where I live) but their first instinct is to run away if they have a chance.

Nice incident of a tourist near where I live picking one up to have a photo taken with it and being bitten in the face and rushed to hospital. He survived which saved the doctor having to put "stupidity" down under cause of death.

eloff• 12 years ago

Here in Panama snakes bite about 2500 people per year (out of 3 million), mostly in the dry season. Here it is common practice to burn the rain forest around settlements to combat snakes. Only about 25 people die, but more have amputations because the most common snakes here are pit vipers with tissue destroying venom. Snakes here are typically not aggressive, the largest danger is stepping too close to one. I've had several near misses with snakes while out running trails in the rain forest (about one snake per month, though usually not venemous.) I've also had a big pit viper attack my car when I drove about a meter from it. You should have seen the face of the guy who washed it when I told him that the streaks were fer-de-lance venom!

tjr• 12 years ago

There's an area not far from where I live (midwestern U.S.) where I've seen numerous snakes. You can just be walking out in a grassy area, and snakes dart left and right trying to not get stepped on. Totally harmless, unless maybe you tried to annoy them.

But I'm guessing you'd be most interested in avoiding more harmful snakes, like, how to avoid being killed by a python or some-such. I too have only seen pythons in zoos.

Synaesthesia2• 12 years ago

Besides the lethality of the disease, we must consider how debilitating it is. Read what it's like to have Malaria.

http://www.gatesnotes.com/Health/What-Malaria-Feels-Like-Mos...

Imagine feeling like that and trying to go to school, work, or take care of your family. It would be impossible. It's undoubtedly contributed to the lack of development in most of Africa.

tokenadult4• 12 years ago

THANK YOU for posting a substantive comment on this article that links to other information on the same topic. Too many of the other comments in this thread are dragging down the level of discourse here on Hacker News. I'll link to some World Health Organization information about malaria[1] here to do my part to make the conversation informative and thoughtful. The malaria parasite microorganism, one of the species of the Plasmodium genus of protozoa,[2] is also being targeted directly both for vaccine prevention and for drug treatment of malaria, but part of the Plasmodium life cycle is obligatorily in living mosquitoes, so to kill mosquitoes is to reduce the load of the parasite and its risk to human populations. This fact (and the fact that mosquitoes transmit other dangerous diseases, including the fatal West Nile virus[3] where I live) is why understanding mosquito control better will be helpful to the world. Indeed, scientists who have considered the issue have been reported to say that a world without mosquitoes at all would be a fine world.[4]

[1] http://www.who.int/mediacentre/factsheets/fs094/en/

[2] http://eol.org/pages/10408873/overview

[3] http://www.cdc.gov/westnile/index.html

[4] http://www.nature.com/news/2010/100721/full/466432a.html

Retric• 12 years ago

I suspect this as a lot to do with why tropical countries are less prosperous despite all the benefits of living in the tropics. Still, I find it somewhat disingenuous to downplay the ~1,200,000 vehicle related deaths as somehow not caused by people.

test1235• 12 years ago

You should read 'Guns, Germs and Steel' by Jared Diamond.

It's a very interesting book about how the civilised world came to be the way it is, for example, why Europe discovered America, and not vice versa.

http://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel

drieddust• 12 years ago

I can't up vote you enough to highlight this aspect of malaria. I know it first hand.

As a child, I went through the horror for 3 consecutive years. After that somehow I developed some kind of resistance and never got it again.

TomGullen• 12 years ago

I think it'd be interesting to see these weighted by animal populations

atmosx2• 12 years ago

"[...] malaria [...] threatens half of the world’s population and causes billions of dollars in lost productivity annually."

billions of dollars in lost productivity?!?!?

NOTE: Not in healthcare. Because there's no health-care Central Africa where malaria does the biggest damage. It causes billions of dollars in lost productivity. Now we need to cure it.

indralukmana3• 12 years ago

So, in indonesia (bill gates recently came here) mosquitos really thrive in all regions. One of the most common and dangerous disease caused by them are (known locally as) "Demam Berdarah" with the literal translation is "Bloody Fever", i don't know if it is the same with the "dengue fever" stated in the article (i have a bad English). This disease is very dangerous especially in rainy season, when there are very many water puddle everywhere and the mosquitos breed. Sometimes hospitals have a very tough time here when the patients start flowing in a very large volumes. So i am grateful to bill gates for giving a grant for solving this problem

masklinn5• 12 years ago

One of the most common and dangerous disease caused by them are (known locally as) "Demam Berdarah" with the literal translation is "Bloody Fever", i don't know if it is the same with the "dengue fever" stated in the article (i have a bad English)

Using wikipedia, the Indonesian "Demam Berdarah" article is linked to the English "Denge Fever" article, so probably.

soneca• 12 years ago

also, in Brazil we call Dengue and the main prevention tactic is indeed to eliminate the "water puddle everywhere" so the mosquitoes can't breed. So, very probably the same.

brazzy• 12 years ago

There is a whole group of such illnesses; the general term is haemorrhagic fever:

http://en.wikipedia.org/wiki/Haemorrhagic_fever

indralukmana3• 12 years ago

Ah yes, it appearantly so it is the same "Dengue Fever". The most common ones here in Indonesia is the ones which caused by mosquitos named "Aedes Aegypti".

We were tought in primary schools here to always be vigilant for this kind of particular mosquitos. They are characterized by a certain colour, "Black and White" stripes on their body.

cloudhead4• 12 years ago

Pretty misleading I'd say.. Malaria kills people, not mosquitos, mosquitos have nothing to do with Malaria. Would be like saying rats are deadly because they carried the plague.

Also I interact with humans every day and I'm still alive.

I understand where it's coming from, but it's more of a historical post-factum analysis rather than a indication of which animals you should stay away from.

frozenport2• 12 years ago

>mosquitos have nothing to do with Malaria

If you get rid of the mosquitos you get rid of most of Malaria.

cloudhead4• 12 years ago

Yes, and if you get rid of humans, you get rid of wars, but the majority of humans don't wage war today.

S_A_P• 12 years ago

That is the same as saying its not the snake that kills you its the poison. Mosquitos do have something to do with Malaria as they carry it, willingly or not. I live in Houston where there are plenty of mosquitos and plenty of mosquito related illnesses/Deaths each year.(West Nile, Bird Flu) Mosquitos are a serious nuisance, and to top it off I am pretty allergic to the bites, mine swell up and itch pretty severely. I would love to see more research put into controlling these things. Regardless of the fact that they are unwitting carriers of Malaria and other disease, they deserve more attention for eradication. Hopefully in a way that doesn't involve blanketing an area with pesticide...

cloudhead4• 12 years ago

Well, the difference is Malaria is a kind of living being in itself, it uses mosquitos to spread. On the other hand, poison is produced by the snake, and the snake uses it to survive.

PhasmaFelis3• 12 years ago

Malaria kills people, not mosquitos

You know, when people say "falling isn't dangerous, it's the sudden stop at the end," it's supposed to be a joke, not a serious proposal.

cloudhead4• 12 years ago

I've been bitten by mosquitos hundreds of times, I'm still alive. Why is that, if mosquitos are so deadly?

Zarkonnen2• 12 years ago

Maxing out my pedantry score, the actual answer is "humans" followed by "snakes". Mosquitos themselves are not dangerous, and malaria parasites are not animals.

r0h1n• 12 years ago

Okay, I'll bite and try to outmax your pedantry:

If a mosquito bite can infect and kill, why isn't a mosquito dangerous?

Alternately, if I take your logic that "mosquitoes themselves are not dangerous", why can I not extend that to humans and say human beings themselves are not dangerous?

masklinn5• 12 years ago

If a mosquito bite can infect and kill, why isn't a mosquito dangerous?

Because it's not the mosquito itself doing that (as opposed to, say, a rattlesnake), it's a parasite hitching a ride on an "innocent" (of that anyway) mosquito. Much like e.g. bats and henipaviruses, bats are a resevoir species but nobody in their right mind would say that Mark Preston was killed by a fruitbat.

bsnape• 12 years ago

How many humans kill other humans with only their bare hands? Humans themselves are not dangerous, and weapons are not animals.

lotsofmangos• 12 years ago

Well, if you insist on that level of pedantry, malarial parasites are protozoa, which is usually considered to be part of animalia.

Zarkonnen2• 12 years ago

Oh right! I tried to figure this out, and thought protozoa were not animals. I withdraw my pedantry. :D

Tyrannosaurs2• 12 years ago

When you're shot dead I'll be sure to point out to the investigating police that you don't consider killers to be dangerous as ultimately it was the gun rather than the killer that caused your death.

;-)

4ndr3vv• 12 years ago

Sorry to be pedantic, but we're discussing deadliest animals, not dangerous ones.

frozenport2• 12 years ago

How about a person with a car?

`Approximately 1.24 million deaths occurred on the world’s roads in 2010` WHO

theandrewbailey• 12 years ago

Also: deer.

jowiar• 12 years ago

And moose, for our hockey-playing friends.

radisb• 12 years ago

I would like to see the exact same graph but having instead as value the humans killed per unit of the animal. I doubt if the mosquito would be on top.

josefresco• 12 years ago

What about a horse? I seem to remember reading somewhere that they caused more human injuries and deaths than many other "dangerous" animals.... or maybe I'm remembering wrong.

anotherevan2• 12 years ago

and vending machines.

jtheory3• 12 years ago

Last month I spent 2 weeks in Rwanda with my wife & daughters, visiting two friends who have been there for about a year. One of them has also spent a lot of time in Tanzania and elsewhere in Africa.

Rwanda is land-locked and largely high-altitude, so malaria is not nearly so prevalent there, but it's still around.

It's already preventable -- we came with a sufficient supply of antimalarial pills, but they're so expensive it's obviously not a solution. We got yellow fever vaccinations before coming -- that was a no-brainer -- and we actively avoided mosquito bites, esp. for the little ones. My friend who has traveled widely in Africa doesn't take anti-malarials -- too pricey -- has gotten malaria, once, and it put him in the hospital for a couple of days.

He says many of the people he knows have had it, multiple times -- it's just a fact of life, and it sucks, but (probably) you'll live, and then have some protection against getting it again.

Gates talks about it as being debilitating -- apparently it's not always so bad, if you've had it before (and people talk about having "a touch of the malaria"!), but generally he's on the mark about the costs.

peterwwillis• 12 years ago

The most common victims of diseases like malaria in countries without access to basic medical resources is children and the elderly. Most of the people who die from malaria are under 5 years old. Out of the 207 million people who got malaria in 2012, only 0.3% of those people died.

In contrast, diarrhea kills more children under five each year (760,000) than all of the people killed by malaria each year. But it's much harder to combat diarrhea because of both the varied nature of its cause/transmission and a lack of clean drinking water. (It is comparatively much easier to treat/prevent malaria than it is diarrhea)

benro• 12 years ago

We did the same thing when we lived in Uganda. Most westerners staying in the country for more than a few months stop taking anti-malarials.

However most places where the expats live have access to antibiotics and to at least 1 or 2 Western (usually British) Doctors/Nurses.

xenophonf• 12 years ago

It really depends on your appetite for risk. One of my colleagues has been taking Lariam for about 25 years, and I usually carry two weeks-worth of extra Malarone doses when I travel (might switch to Lariam for my next trip).

masklinn5• 12 years ago

It's already preventable -- we came with a sufficient supply of antimalarial pills

There's just one problem with that one — aside from costs for third-world regions: http://phenomena.nationalgeographic.com/2014/03/25/can-we-be...

Gates talks about it as being debilitating -- apparently it's not always so bad

At the social level it is debilitating, without good treatments there's a high risk of acute respiratory distress and renal failure, and more importantly in children cerebral malaria causes direct brain damage and regular malaria causes anemia, leading to increased risks of cognitive deficits and behavioural disorders.

jtheory3• 12 years ago

> It's already preventable -- we came with a sufficient supply of antimalarial pills, but they're so expensive it's obviously not a solution.
There's just one problem with that one — aside from costs for third-world regions: http://phenomena.nationalgeographic.com/2014/03/25/can-we-be...

Good point -- the expense is serious, but also widely using low levels of drugs that are effective treatments as antimalarials means giving the parasite lots more great opportunities to evolve resistance (which is already happening, and is a serious upcoming problem).

At the social level it is debilitating...

Yup, I agreed with Gates' conclusions; I was trying to share some direct experience.

jmnicolas• 12 years ago

I'm surprised by the wolves. I though it was quasi a myth that they killed humans.

guscost4• 12 years ago

Not to be That Guy, but millions and millions of these deaths were preventable. The UN vote to effectively ban DDT has got to be one of the worst public health disasters in history. It is sickening.

http://www.fightingmalaria.org/article.aspx?id=1862

http://perc.org/articles/legacy-ddt-ban

http://www.scientificamerican.com/article/ddt-use-to-combat-...

http://www.thenewamerican.com/tech/environment/item/15583-dd...

zerohm2• 12 years ago

Why trade a public health disaster for an environment disaster that will likely lead to a different public health disaster? Current restrictions seem reasonable.

"The Stockholm Convention, which took effect in 2004, outlawed several persistent organic pollutants, and restricted DDT use to vector control. The Convention has been ratified by more than 170 countries and is endorsed by most environmental groups. Recognizing that total elimination in many malaria-prone countries is currently unfeasible because there are few affordable or effective alternatives, public health use is exempt from the ban pending acceptable alternatives."

http://en.wikipedia.org/wiki/Ddt#Restrictions_on_usage

guscost4• 12 years ago

Why trade a public health disaster for an environment disaster that will likely lead to a different public health disaster?

This is a false dichotomy. And regarding your other point:

“Every life saved this year in a poor country diminishes the quality of life for subsequent generations.” -Paul Ehrlich, 1968

“By using DDT, we reduce mortality rates in underdeveloped countries without the consideration of how to support the increase in populations.” -Michael McCloskey, 1971

“So my chief quarrel with DDT, in hindsight, is that it has greatly added to the population problem.” -Alexander King, 1990

"An end to the continued domestic usage of the pesticide was decreed on June 14, 1972, when William D. Ruckelshaus, Administrator of the Environmental Protection Agency, issued an order finally cancelling nearly all remaining Federal registrations of DDT products."

http://www2.epa.gov/aboutepa/ddt-ban-takes-effect

"WHO actively promoted indoor residual spraying for malaria control until the early 1980s when increased health and environmental concerns surrounding DDT caused the organization to stop promoting its use and to focus instead on other means of prevention."

http://www.who.int/mediacentre/news/releases/2006/pr50/en/

"Thanks largely to the use of DDT in Namibia, malaria related hospital admissions and deaths fell by 92% (29,059 to 2,264) and 96% (1,370 to 46) between 2001 and 2009. Similar trends have been seen in Botswana, South Africa, and Swaziland. For these benefits to be outweighed by risks requires reproducible evidence that DDT is dangerous, but none exists. WHO’s latest assessment found no evidence for concern “about levels of exposure for any of the end-points that were assessed” in carcinogenicity, reproductive toxicity, or developmental toxicity.

Yet despite this endorsement and admirable malaria control results, UNEP is trying to eliminate DDT again. As major UNEP donors, including the European Union, have endorsed WHO’s position, UNEP’s motivations are unclear."

http://www.bmj.com/content/345/bmj.e6801?ijkey=H4KijaZlhGvkD...

jcromartie• 12 years ago

This is hyperbole. The DDT "ban" was on agricultural use. Many countries have continuously used DDT for malaria prevention, and some countries have successfully controlled malaria without any DDT at all.

GFK_of_xmaspast2• 12 years ago

One of the things about DDT, in addition to everything else, is insects can and do develop resistance to it: http://en.wikipedia.org/wiki/DDT#Mosquito_resistance

tzs• 12 years ago

DDT spread way too broadly in the ecosystem, to species it had never been tested on, and it persisted a long time. It was known to interfere with critical species such as nitrogen-fixing bacteria. This is not something you want to mess around blindly with, which is what we did by putting DDT into widespread use without adequate testing.

There are three effective ways to control insects.

1. Poison them with something that is dangerous to a wide variety of life.

2. Poison them with something that is narrowly targeted to the species you are trying to control and is harmless to other species.

3. Deal with them mechanically, such as by crushing them or tearing them apart.

DDT and similar pesticides take the #1 approach. To do that safely you have to carefully control the spread of your pesticide so that it doesn't spread to species you do not want to harm. You can do this by being very careful in how it is applied, and designing it to break down quickly and not spread beyond the application area. We failed in this aspect with DDT.

The #2 approach is quite feasible. The way it works is that you base your pesticide on hormones of your target species. Insects are essentially biological robots running conceptually simple and very inflexible state machines. Various hormones control this, triggering various programs that run on the state machine. For instance, there might be a particular hormone that activates in the males when the weather changes, triggering in males a flight to find a female, and after that program runs the male dies. A different hormone might trigger female mating behavior.

Entomologists can study that species, and identify the various behavior programs built into the insect state machine, and figure out what hormones active which programs. Then a pesticide can be designed that mimics the hormone that starts the male mating subroutine. Spray that on them when it is not the right time of the year, so the females are not having their mating program trigger, and the males will go do their (now futile) mating flight and die.

The best part about this is that it is safe for other species, because these program control hormones for one species are almost always harmless to other species up the food chain. (To be up the food chain from something, you kind of need to have evolved to not be bothered by its hormones).

Another nice thing about the #2 approach is that the pests do not develop immunity. If an insect develops immunity to, say, the hormone that triggers its mating flight, then it is not going to mate when that trigger fires naturally, and so whatever mutation provided that immunity dies off.

The #3 approach is also quite feasible...and no, I don't mean importing cheap migrant workers to go out with tweezers in the fields and crush insects. :-) I'm talking about finding an insect the preys upon or is a parasite to the insect you want to control, and using it. Entomologists can study a pest species and identify what its enemies and parasites are (and there usually are some), and then you can introduce those to control the pest species. Unlike higher forms of like, like reptiles and birds and mammals, insects tend to be very picky about what they prey upon or what they are parasites to. If you've got a particular species of invasive insect from Florida destroying your California citrus crop, and you import the species of parasitic wasp that kills the pest, when it kills them it does not turn to some other species for hosting services. It dies.

The big problem with #2 and #3 is that there are a lot of insect species, and a lot of predator and parasite species, and not a lot of entomologists. This is discussed in the excellent book "Life on a Little Known Planet" by Howard Ensign Evans [1]. He was one of the worlds leading experts on parasitic wasps. There are hundreds or thousands of species of them, most very small (the size of pinhead or smaller). In the book, he tells the story of that pest destroying the California crop. Officials did try to import the parasitic wasp from Florida that kept the pest in control there.

It failed. Eventually, after the crop was destroyed, they found out why. It turns out that what was thought to be one species of parasitic wasp was actually two, which are almost identical, except one of them was NOT a parasite for the particular species they were trying to control. With hundreds of species of parasitic wasps and very few parasitic wasp experts in the world, no one had looked at this one species close enough to have noticed that there were really two species.

The kind of observation and experimentation is takes to learn enough about the insect state machines to make the hormone mimicking pesticides, or to learn enough about an insect's predators or parasites to effectively and safely control the pest biologically, takes a long time. Industry is not interested in funding that. They want entomologists to work on type #1 poisons, not to spend 20 years in the lab studying one species to identify a key hormone.

Academic entomologists who want to pursue these studies aren't pulling in the big grants, either. Evans tells of having to advise a graduate student to NOT specialize in parasitic wasps, despite the student's interest in and talent at it, because he would not be able to get funding for research in that area.

[1] http://www.amazon.com/Life-Little-Known-Planet-Biologists/dp...

guscost4• 12 years ago

1) Can you provide examples of some experiments which were a bit more conclusive than all that eggshell stuff [1]?

2) I'm not sure, but I think the big problem with this approach is that the pest in question can quickly evolve tolerance for the targeted pesticide. DDT resistance has not prevented astounding success with the recent vector control programs in Namibia and elsewhere. And it is much cheaper than the latest targeted pesticide that Monsanto wants the UN to subsidize.

3) Sounds interesting, but Malaria is not the kind of problem where experimenting with ecosystems and writing academic papers about mosquito predators is really a practical approach. Hundreds of thousands are still dying every year and a simple vector control strategy has been known to work for decades.

[1] http://reason.com/archives/2004/01/07/ddt-eggshells-and-me

mattmaroon• 12 years ago

Not sure where he got 10 wolf deaths per year. The average number of wolf deaths per century is less than that. Not the most relevant comment I suppose, but it makes me curious about his data collection process.

tootie• 12 years ago

Globally?

rgejman• 12 years ago

Cows ought to be on that list as well. They kill 10-20 people per year in the US alone. http://tierneylab.blogs.nytimes.com/2009/07/31/dangerous-cow...

rokhayakebe• 12 years ago

So much for dogs, Man's best friend.

sethammons• 12 years ago

Can someone with better search-fu help me understand how freshwater snails kill humans?

Google is only giving me this same blog post.

tokenadult4• 12 years ago

I knew the name of the disease before I started the search, but since you asked for search-fu, I'll mention that I Googled "snail fatal disease," which led to a Wikipedia article[1] and searching the article page for the word "snail" led to the specific section about the disease. The disease name, "schistosomiasis," is of course an even better search term for finding out more information about the disease.

AFTER EDIT: using the same word string from your question here, "how freshwater snails kill humans" (NOT searching as a phrase, but as a string of words) on Google does indeed first bring up the Bill Gates blog post, but a few results below the search results show a World Health Organization document on freshwater snails[2] that largely answers the question.

[1] https://en.wikipedia.org/wiki/Neglected_tropical_diseases#Sc...

[2] http://www.who.int/water_sanitation_health/resources/vector3...

jcomis• 12 years ago

The snails harbor a parasitic worm which they pass on to the water supply. The worms then use humans as a host and lay a large amount of eggs in the host. The worms and the eggs themselves cause an enormous strain on the hosts liver, kidneys, digestive, and urinary system. They essentially migrate through the body to get to the liver where they can lay thousands of eggs a day. Most eggs then enter the intestines in order to pass out of the host and back into the water supply to mature in snails and start the cycle over.

The real danger is you don't need to drink the water, just come in contact with it. So stepping in a puddle could cause infection. I was just in Colombia and there was a campaign trying to raise awareness on this so I learned a bunch about it. Scary stuff!

orky562• 12 years ago

Same link and same title? I'm confused https://news.ycombinator.com/item?id=7665106

tokenadult4• 12 years ago

Here the submission is not with the canonical URL, which spoofed the duplicate submission detector. It's too bad the previous submission had only one comment, a crap comment, so it's a good thing the article was submitted again.

orky562• 12 years ago

Agreed. Must have missed the difference in URL.

brianbreslin• 12 years ago

One of the key innovations in the development of the Panama Canal was the fighting of malaria/yellow fever. Without understanding this, the canal wouldn't have been built, and Panama would probably look a lot more like Nicaragua than like Hong Kong.

http://www.pbs.org/wgbh/americanexperience/features/general-...

swehner• 12 years ago

For comparison, wikipedia's list of causes of death ranked by frequency:

https://en.wikipedia.org/wiki/List_of_causes_of_death_by_rat...

calbear81• 12 years ago

What about the Photonic Fence that Bill Gates funded (http://intellectualventureslab.com/?page_id=6738)?

I think it was criticized because it required electrical power to run and that would have been a no go in sub-Saharan Africa but I imagine it would work great everywhere else.

brianstorms• 12 years ago

"What am I, chopped liver?" - every bacterium and virus, everywhere

TheCoelacanth• 12 years ago

Neither of those are animals.

reuwsaat• 12 years ago

It's funny[0] that "Number of deaths" = "Number of people killed by animals". Perhaps if humans allowed that the deaths other animals is also of consequence we'd have a healthier relationship with nature. It's ranting about your home being destroyed by a hurricane, especially since you just rebuilt it after last years hurricane. Deaths by malaria and the destruction caused by hurricanes always terrible, but we need to look into mitigating such harm both by working with and against nature (which we are a part of, so I take issue a little bit even making that distinction, but, for the sake of discussion).

[0] funny = sad

islon• 12 years ago

Mosquitos are like heart attacks: they kill thousands/millions but they are boring so nobody care.

Sharks are like terrorists: they kill just some dozens but are super scary.

The Deadliest Animal in the World

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