Universal "Death Stench" Repels Bugs of All Types 248
Hugh Pickens writes "Wired reports that scientists have discovered that insects from cockroaches to caterpillars all emit the same stinky blend of fatty acids when they die and that the death mix may represent a universal, ancient warning signal to avoid their dead or injured. 'Recognizing and avoiding the dead could reduce the chances of catching the disease,' says Biologist David Rollo of McMaster University 'or allow you to get away with just enough exposure to activate your immunity.' Researchers isolated unsaturated fatty acids containing oleic and linoleic acids from the corpses of dead cockroaches and found that their concoction repelled not just cockroaches, but ants and caterpillars. 'It was amazing to find that the cockroaches avoided places treated with these extracts like the plague,' says Rollo. Even crustaceans like woodlice and pillbugs, which diverged from insects 400 million years ago, were repelled leading scientists to think the death mix represents a universal warning signal. Scientists hope the right concoction of death smells might protect crops. Thankfully, human noses can't detect the fatty acid extracts. 'I've tried smelling papers treated with them and don't smell anything strong and certainly not repellent,' writes Rollo in an e-mail. 'Not like the rotting of corpses that occurs later and is detectable from great distances.'"
Re:This is nonsense (Score:1, Informative)
It certainly does jive with evolution as currently understood. There are plenty of examples where evolution has resulted in genes that don't help you directly, but help those around you. In the fairly common case that those around you are your relatives, and thus likely to share that gene, natural selection will still be pushing for it, because it is making others with that gene more likely to survive.
There has been a lot of research done, for example, on why soldiers are willing to die for their community (death being pretty much the end of the line for your genes...). The answer is that he's protecting his parents, siblings, and children, who are going to propagate the heroism gene, while the cowardly guy who runs away and survives might get his relatives killed, thus lowering the number of copies of the cowardly gene.
And before you say "but that's just human emotion!", no, mother bears will fight and die to protect their young. Lots of flocking birds have "lookouts" that will squawk when danger approaches, which statistically is going to cause the lookout to be a lot more likely to get eaten, but protects his flock. Most herd animals have group behavior where adults will ring the outside of the herd to protect the young at the center of the herd (even adults who don't have direct children, they're still willing to protect the presumably more distant relatives of the herd)...
Remember, evolution is tied to genes, not individuals. And your genes are statistically tied to your community and your relatives.
Re:Prolly not going to work. (Score:2, Informative)
It doesn't surprise me that penicillin (an antibiotic) doesn't work too well against a virus. That's not a mutation.
Perhaps you meant bacteria that are immune to penicillin (which, in many cases, are the result of stupid people insisting on trying to treat viral infections with antibiotics).
Re:Crops (Score:3, Informative)
How are they going to use this for protecting crops? If ants are repelled, wasps and bees will be, too, and there goes your pollination.
Still useful (if it really works) for protecting fruit though. Once the blossom is gone and the fruit starts to develop, pollination is no longer an issue.
Re:Bring out your dead ! (Score:2, Informative)
I have ants where I live, and I've experimented by killing and collecting dead ants, then crushing them and spreading the juices around.
The ants don't care about their own dead, apparently. I find trails of ants all the time where dead ants are scattered along the trail. It doesn't deter them one bit...
Re:Crops (Score:1, Informative)
This could be still usefull for crops that are self pollinating. Not every crop needs bees.
Less nonsense (Score:3, Informative)
Maybe for some bugs, but for those nasty caca roches, I get a bowl, wipe the top 4 inches around inside with vegtable oil then put whatever inside... coffee grounds, bananas... whatever... There are tons of dead ones in there but that doesn't stop more from coming. Also, cockroaches are cannibals.
Got a roach problem? Cheap boric acid, sold in plastic bottles everywhere. Don't dump it, pour it, spoon it. Don't waste time preparing mixtures of food and boric acid. Snip the top off of the plastic top. Tip the bottle a little bit, and squeeze. Practice until you can create clouds of fine particles floating in the air. Globs and clumps of white powder do you no good at all - you want a very fine cloud to float out, so that it can settle and coat everything.
Get rid of kids and pets for a couple days - some people say this stuff is bad for them.
Proceed to walk all around the house, puffing powder into every corner, nook, crevice, and cranny. Don't forget to crawl under the sink, behind the toilet, behind doors - everywhere. Get the cracks between window frames, behind mirrors, closets, every where! Got a crawlspace under the house? Get down there and puff away. Don't forget the attic, if you have one. Powder the water heater, and the cubby hole that it stands in. (gas heater? this stuff isn't flammable, but for safety sake, you might turn the gas off for a few hours) Get under and behind appliances like microwaves, refrigerators, freezers, washers, dryers and dishwashers.
Perhaps most importantly, puff this stuff into all cracks between baseboards, paneling, corners of rooms, door frames. If you can get a tool behind a baseboard or panel, pry it out slightly to puff dust behind it.
I've cleaned out unbelievable infestations in repossessed mobile homes. They don't come back! Three or four of those 1 pound bottles will take care of the largest single wide mobile home, I've used six in doublewides.
If no one is actually living in the home, there's no need to "clean up" right away. Leave everything like it is, so that if you've missed anyplace, those cannibal roaches come out to consume the dead.
When it is time to clean up - just sweep and mop floors. There's no need to vacuum the dust from inaccessible places. Just leave it to aid in prevention of future infestations.
For ten dollars or less, you can accomplish what the high dollar pest control companies cannot.
NOTE: Dusting for roaches may be less effective in the moist basements inhabited by geeks.
Re:Crops (Score:3, Informative)
Re:This is nonsense (Score:3, Informative)
Your understanding of evolution is incorrect. Evolution isn't something an animal "does" or even something nature "does". It's just the simple fact that ANYTHING that leads to better reproductive success will lead to more offspring and gradually replace animals that don't have that SOMETHING.
Evolution is not hard to understand, it's just common sense once you understand it.
Imagine two valleys separated by a hard to cross mountain ridge. In one valley some animals develop a random mutation that gives off a strong "death stench" when they die. Over time the other animals in the valley learn or evolve an aversion to this smell because staying away from things that kill you is an advantage.
The animals in this valley will avoid certain contagious or dangerous deaths because of this aversion. They will prosper slightly more than the animals in the next valley that don't have this combination. Over a long period of time the population in this valley grows enough that they start migrating into the other valley and over a long time they dominate and replace the animals in the next valley because of their ability.
Re:Crops (Score:5, Informative)
How are they going to use this for protecting crops? If ants are repelled, wasps and bees will be, too, and there goes your pollination.
Corn [wikipedia.org] is pollinated by wind. I'm not going to bother to find sources for each kind of corn, but here's links for maize [osu.edu] (American corn), wheat [answers.com] (European corn), and barley barley [wikipedia.org]. (I guess that link only indicates that Barley self-pollinates, not pollinates by wind. whatever.) Rice [wikipedia.org] is also wind-pollinated.
Potatoes [cornell.edu] don't need to be pollinated at all.
Therefore, if a product is developed from cockroach juice, it might be most useful for these kinds of crops. Note that "cereals" and "roots and tubers" are the 1st and 3rd most produced [wikipedia.org] type of crop.
Re:Prolly not going to work. (Score:4, Informative)
The very high degree of conservation of this trait across species suggests that there are already strong selective pressures to maintain it. Selective use of this stuff is not likely to counter that. Also most evolution happens through frequency shifts of alleles already present in the population, not through creation of new alleles by mutation. Given the long evolutionary history, there may not be many non-functioning alleles for this trait to promote. Mutations are random and infrequent, and most are lethal. It could be many, many years before a suitable mutation arises.
Re:This is nonsense (Score:3, Informative)
I know I'm being pedantic, but am I the only person on /. that knows the word is "jibe", not "jive"?
Re:This is nonsense (Score:1, Informative)
Sigh... let's all say it at once. Evolution works on populations not individuals.