Science blog
Orbital mechanics affect methane levels
Antarctic lake keeps its secrets for now
How snakes lost their legs
Researchers ponder cancer origins
Forming social networks a no-brainer
'Niceness' partly genetic, say scientists
Omega-3 may keep blindness at bay
Coral shines light on rainfall records
Old bone proves Lucy was no swinger
Scientists unlock cosmic ice riddle
Study links pesticides to Parkinson's
Digital world growing faster every year
Energy drinks put kids at risk: report
Robotics speed up cancer drug development
Zinc cuts short the common cold
Counting kicks in at 18 months
NASA spacecraft unravels comet mystery
Astronomers dig up cannibalised galaxy
Study links extreme weather to climate change
Turkey quake gives warning clues
US scientists build first 'antilaser'
Website meltdown leaves scientists fuming
Earth 'unrecognisable' by 2050: experts
Canola fungus genome unravelled
Cricket wimps use perfume to find mates
The cricket world is not above using chemical enhancement in a bid to get the girl, according to an Australian study.

Insect skins, or cuticles, are coated with a layer of fatty acids that prevent water loss. The composition of these chemicals can also provide information about species identity, sex and past mating activity.

The study, by researchers at the University of Western Australia's Centre for Evolutionary Biology, shows that these chemicals can undergo rapid changes in composition and reflect changes to an individual's social status.

In the research, published today in the Proceedings of the Royal Society B, the authors show for the first time in any species, males undergoing short-term changes in their chemical 'make-up' in response to a dip in dominance status.

"Male dominance status can be frequently challenged and is therefore a potentially unstable trait," co-authors Dr Melissa Thomas and Professor Leigh Simmons write.

"For pheromones to honestly reflect a male's current social status, they would be required to mirror such changes in status."

For the study, Thomas and Simmons analysed the chemicals that the Australian field cricket (Teleogryllus oceanicus) produces on its skin.
Equivalent to exotic plumage

Male crickets were found to alter the chemical composition of their fatty coat in response to aggressive interactions with other males.

Thomas says in mating terms those chemicals - the cuticular hydrocarbons - are the equivalent of exotic plumage on male birds and play a similar role in attracting females.

The study shows that dominant males, on losing a fight with another dominant male, create a chemical signature resembling that of a subordinate male.

This could help compensate for their lost fertilisation success, Thomas says.

For the study the researchers first ranked the crickets through a series of fights. Only those that won all their bouts, the dominant males, and those that lost all their bouts, the subordinates, were used in the study.

The status of the crickets was then forcibly changed by placing two dominant crickets and two subordinate crickets together and allowing them to fight.

Thomas says it was easy to determine which cricket had won as subordinate males would display avoidance behaviour while the winning dominant male would produce an aggressive victory song.

Samples of the cuticular hydrocarbon were taken and analysed, and showed that previously dominant males quickly changed their hydrocarbon profile to more closely resemble a subordinate male.

Thomas says this chemical change could help the previously dominant crickets increase their mating success.

"Although males cannot force copulations, dominance status does determine a male's ability to attract females via acoustic signals," she says.

"Dominant males will produce calling and/or courtship songs in the presence of subordinate males, whereas subordinate males are suppressed in their courtship song through intermittent attacks by the nearby dominant male."
Like wearing strong cologne

In nature subordinate males appear to compensate for this disadvantage by producing a relatively larger proportion of certain cuticular hydrocarbons that have previously been shown to increase male attractiveness to females, a bit like human males wearing strong cologne.

But in the study subordinate males that won a fight did not change their chemical profile to match that of a dominant cricket.

Thomas says this suggests males of different social competitiveness are either genetically predisposed to this chemical plasticity, or that social experience can strongly influence a male's decision in subsequent interactions.

But she says further research is needed to find out which of these factors is the dominant influence for what happens in crickets.

"It's pretty complicated for a little insect," says Thomas.

She says understanding how the hydrocarbons are used and work is the first step in discovering whether this knowledge could have a role in pest management.

Brain efficiency comes from parents
Backward bending light key to stealth
Signs of 'alien life' found in meteorites
Accurate blood test for Down's
Disaster volunteers at risk: study
Elephants smart as chimps, dolphins
Gadgets ruining people's sleep
Why skin doesn't dissolve in the bath
Astronomers find old heads in a young crowd
Paper leads to perfect beer head
Researchers locate brain's loudness map
Jamming may leave GPS in the wilderness
Pain washes guilt away
Quake could alter Tokyo risk: experts
Japan meltdown not like Chernobyl: expert
Dreamtime astronomers understood meteors
CERN restarts search for cosmic origins
Nuclear Contamination: What to Do
Bet-hedging 'key to natural selection'
Humans age same as other primates
US overdue, under-prepared for huge quake
Sperm's egg-seeking secrets revealed
Lasers to nudge space junk out harm's way
Researchers uncover gastro's sugary secret
Kepler probes inside swollen red giant
Randomness could 'improve democracy'
Moonageddon: Apocalypse not
Museum unveils Columbian mammoth
Ink-jet inspire scientists to make skin
Seaweed offers clues against malaria
Christchurch quakes may be connected
Solar storms pose risk to technology
Study finds fences thwart cane toad
Mobile phone alters brain activity
Sticky dots approved for clinical trial
Humans stink worse than other animals
Putting the bounce in carbon balls
Sulphur secrets uncovered
Cool laser makes atoms march in time
Hot flashes may be a sign of good heart
Scientists see the birth of a new planet
X-ray expectations change search methods
Eucalypt-harming fungus here to stay
Life elements came from outer space
Cricket wimps use perfume to find mates
Orphan planets could support life
Speech lights up visual cortex in blind
How the Sun loses its spots
Cancer resistance mechanism found
Fungus turns Amazonian ants into zombies
Tiny grains record solar system's infancy
Antarctic ice forming beneath glaciers
Visit Statistics