Universal "Death Stench" Repels Bugs of All Types

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.'"

Comments

This is nonsense

[Rooked_One]

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.

Re:This is nonsense

[ShadowRangerRIT]

I think bulk breeding and crushing of roaches would likely be a fairly effective means of building these compounds in bulk (assuming, of course, that roaches have a decent amount of these chemicals in them). Paraphrasing and condensing from Wikipedia: In favorable conditions, one female roach can, in her one year lifespan, produce 300-400 offspring, and she only needs to be impregnated once to do so (though the eggs are only laid in groups of ~40 at a time). Aside from one or two commonly available nutrients, their gut bacteria synthesize all other nutrients required to live from whatever they eat, from wood to postage stamp glue to corn oil, so you can feed them otherwise worthless semi-edible plant matter as a form of accelerated composting.

Besides, I think we can safely say that no matter how much of a threat we pose to the survival of other species (say, most of the world's fish stock), we're in no danger of running out of roaches. And aside from PETA, not a whole lot of people are going to protest a roach crushing facility that enables them to repel roaches. Just don't build it too close to people, or you'll get a whole NIMBY movement going.

Re:This is nonsense

[NikLinna]

Bugs killed by violent crushing and bugs that die of starvation or age probably emit different chemicals. A few months back I read about how bees carry their dead out of the hive, and identify them by similar chemical markers. If the researcher dabbed a live bee with the chemical, its sisters would drag it "kicking and screaming" out of the hive and would not let it back in. :-)

Smelling death

[spgass]

The article says humans cannot detect the fatty acid extracts, but I wonder if this theory expands to mammals. After getting a couple of squirrels with my tube trap, squirrels now seem afraid to enter. My wife thought they might "smell death"

Folklore

[Maximum Prophet]

Several gardening experts claimed that grinding up bugs and spraying them on crops would repel bugs, but field tests have shown no special results. Perhaps this only works in confined spaces like were cockroaches live.

Re:Folklore

[BeardedChimp]

By sprinkling the bugs over a large area you will quickly dilute the fatty acids. It's very possible that if they take the compound and produce it in large quantities that this approach would work.

Re:Perfect bug repellent?

[danking]

Well I think you would have to leave it around for it to start rotting, I assume most people clean up the squashed roach after they squash it.

Is this new?

[Nerdposeur]

A few decades ago, Edward O. Wilson proved that ants mark their trails with scent by removing their organs individually and smearing them around. Eventually he found one that would cause them to follow the trail, and would demonstrate his discovery by writing his name in ants.

I heard a recorded lecture where he told this story, and he also mentioned that they discovered the "dead ant" smell that would signal the colony that "this one is dead, go put it on the pile." When they put the scent on a live ant, the other ants would carry it off to the pile, ignoring the fact that it was squirming the whole way there. And until the stinky ant cleaned itself off enough, they would keep putting it back every time it left the pile.

Re:Bring out your dead !

[Shakrai]

I have ants where I live

I would hope so, unless you are posting from the ISS ;)

The ants don't care about their own dead, apparently

Actually a lot of ants will collect their dead. It's really quite amazing to watch too.

Call me a skeptic

[daveywest]

This seems like bunk to me. I've cleaned some very nasty rentals, and I've removed roach grave yards by the pound. Every roach I've ever seen doesn't bat an eye at eating their departed comrades.

Re:Bad plan, darlings.

[inviolet]

The problem here is capitalism doesn't care -- only protecting high value targets would be the sensible precaution, but why only do that when can make millions, even billions, for a few years until the resistance is developed? And nevermind the ethical implications of short-circuiting a natural defense mechanism -- we might give cockroaches and other insects, that make up a significant amount of the biomass, the ability to spread diseases on a massive scale, since they aren't afraid of their dead anymore.

That may be the very thing that prevents the bug population from ever developing a resistance to this. Any group that does, will be exposed to the perils that they were once protected from (via their aversion to the smell).