About Science
Study reveals why the leopard got its spots
Allergy risk linked to time of first trimester
Hubble reveals furthest galaxy yet
Scientists confirm water from lunar probe
Researchers power up tiny batteries
Plants clean air better than expected
Haiti fault capable of another big quake
Japanese man joins growing genome ranks
NASA releases report into balloon crash
Tree's ability to soak up CO2 has limits
Ground coffee helps robot get a grip
Assassin bugs lure arachnid snack
Research reveals spring in ostrich's step
Lizard gender bends at altitude
Study suggests early primates out of Asia
Flamingos boost their colour to find a mate
Globular clusters more than one-off event
Ancient Africans first to use sharp tools
Grass could turn toxic waste into energy
Earth-like planets may be common
Natural born cell killers
Fingers spot typo ahead of the brain
Ecofriendly styrofoam from milk and clay
Study proves exercise boosts immune system
Assassin bugs lure arachnid snack
Australian researchers have uncovered the sophisticated vibrating techniques used by the assassin bug to turn the tables on unsuspecting spiders.

The process, called aggressive mimicry, lures the spider within attacking range of the bug, immediately before turning it into a "spider milkshake".

Dr Anne Wignall and Associate Professor Phillip Taylor of Macquarie University in Sydney outline the spider-eating assassin bug's (Stenolemus bituberus) vibrating technique in a paper appearing today in the Proceedings of the Royal Society B.

It follows on from their previous paper, which focussed on the assassin bug's behaviour.

"This paper takes a more experimental approach," Wignall says, "we know that they're attracting the spiders somehow, but how are they doing that, what mechanisms are they using? So we looked at the structure of the vibrations, and at the spiders responses."

Under controlled conditions, Wignall and Taylor introduced a variety of things into webs of spiders from the Acharaeanea genus. They monitored the different vibrations created by male spiders, leaves, and two common prey animals: fruit-flies and aphids.
Treading a fine line

They found that the vibratory signature that the assassin bugs created most closely resembled that of prey insects.

But the would-be assassins must enter the spider's domain, and they tread a fine line between eating and being eaten.

Wignall says that it wouldn't be in the bugs' interests to be exact mimics, and that the surprising thing was to see just how finely controlled the vibrations were.

"For mimicry to work it doesn't have to be exactly the same, it just has to work. So they're not mimicking signals like the impact when a fly first hits a web. That produces a really loud high frequency vibration," she says.

"They're also not mimicking things like a fly buzzing its wings, a really fast movement, really high amplitude, higher in pitch; that would elicit a highly aggressive approach from the spider. This is not what the bug wants."
Sucked in, sucked dry

It all comes down to how well they can control the spider's responses, to slowly bring it closer. Wignall says the hunt can last for hours as the bugs slowly and carefully manipulate a spider's reactions.

"The assassin bug moves very carefully onto the web and it begins plucking the silk with its forelegs," she says.

"If it's not getting a reaction from the spider it will move a little further onto the web, move around, pluck a little bit more. Once the spider begins approaching it will often stop signalling and the spider will approach very slowly because it's not getting signals any more. Then it will resume plucking."

"Once it's [within striking range], the assassin bug will tap the spider gently with its antennae once or twice as it moves into position over the body of the spider. Then it grabs the spider really quickly and tightly with its forelegs and stabs it with its mouthparts, like a reinforced modified sharp straw.

"Usually the spider stops struggling within a few seconds. Then the bug starts to suck out the insides, kind of like a spider milkshake."

Wignall says the next step in their research is to look at the spider's decision making process.

"We're not sure what the spider's actually latching onto to say that this is prey, so we're going to concentrate on how the spiders actually recognise different stimuli in the web."

Researchers put spark into scramjets
Fish found making their own 'mozzie' nets
Japan confirms asteroid dust on outback probe
Genetech pioneer awarded science prize
Scientists capture anti-matter atoms
Study reveals Icelandic eruption build-up
Astronomers spot galactic intruder
Open-mouthed laughter appreciated most
Financial crisis causes dip in CO2 levels
Puberty genes linked to body fat
Face shields needed for combat: study
Organically-grown vegies not more nutritious
Bloodstains could give age away
Models show pterosaurs flew long, slow
Marsupial carnivores were underestimated
Massive black hole collision revealed
Jet-lag causes long term memory loss
Sunken tanks could detect secret nukes
Dino demise supersized the mammals
Binge drinking linked to heart disease
Cassini sniffs oxygen on Saturnian moon
Image shows echoes from before big bang
Research uncovers diamond's soft side
World warmer, but trends at odds: report
Humans caused megafauna demise: expert
The world: Four degrees warmer
Blood vessels show pollution, heart disease link
Young great whites don't have the bite
Dolphin social network good for calves
Is fish-oil Alzheimer snake-oil?
Cosmic rays trace Sun's journey through space
Marsupial mole mystery solved
Scientists warn of new polio virus strain
Oldest known stone axe found in Arnhem Land
Fly-by captures first comet photos
Dead quasar's ghostly glow reignites debate
Mum and Dad tell us how to wear our genes
New images expand solar flare knowledge
Experts urge caution on Snowy cloud seeding
First little Big Bangs created at CERN
Tarantulas help map the fear factor
Neanderthal brains developed differently
Whales showing more sun damage
Bush cricket has the biggest balls of all
Giant gamma bubbles found in Milky Way
Complex life possible earlier than first thought
Happiness evades wandering minds?
Cat lapping defies gravity
Physics unravels wet dog shake
Hubble captures rare galactic view
Early wrinkles no sign of an early grave
World's forests suffer from 'leakage'