Archive for Saturday, August 30, 2008
Flies get a jump on swatters, study finds
A Caltech bioengineer and an associate film a fruit fly and find that it first jumps away from a threat before taking wing. This means fly swatters should lead the prey like a trapshooter.
Ever wonder why it is so hard to swat flies?
It’s because they don’t just fly away from impending doom. They first jump in a direction that takes them away from the swatter, said Caltech bioengineer Michael Dickinson.
The neurochemistry of the fruit fly’s jump response has been thoroughly studied. So-called giant neurons in the insect’s brain, the biggest in the fly, sense the shadow of an approaching object and fire, propelling the fly into flight. Researchers had thought that was all there was to it.
But Dickinson and graduate student Gwyneth Card took high-speed digital movies of fruit flies as a black disk dropped toward them.
They reported Thursday in the journal Current Biology that, about 200 milliseconds before impact, the fly’s tiny brain calculates the location of the threat, then maneuvers its legs into the optimum position to jump out of the way.
If the threat is coming from the front, the fly moves its middle legs forward and leans back, then jumps backward. If the threat is from the back, it moves its middle legs backward and jumps forward. If the threat is coming from the side, it leans its body to the other side before jumping.
“It’s like a gymnastics maneuver,” Dickinson said. “It kicks into the air with its legs, then the wings take over.”
When Card and Dickinson removed the insects’ middle legs, which provide jumping power, the insect still leaned in the direction it needed to go before lifting off with only its wings. If they removed the wings, the flies could still jump out of the way of the threat.
As for practical applications, Dickinson said fly swatters should lead the fly like a trap shooter, anticipating the jump. The knowledge of how they launch could also help the many labs trying to build robot insects.
- Report to Congress: Gulf War syndrome is real
- Automakers' pain felt far beyond Detroit
- After more than 400 lawsuits, disabled man can sue no more
- CSU may cut future enrollment by 10,000
- Lincoln and the myth of 'Team of Rivals'
- Soccer team helps Westmont College rise from ashes
- Price of Southern California homes falls 41% from peak
- Museum has thousands of sports memories on display
- Small spark can mean disaster for home
- How Paramount let 'Twilight' get away
- Carona trial witness says he used perk to win DUI suspect's release
- Democrats opt not to reprimand Joe Lieberman
- At Arnold Schwarzenegger's behest, Rob Lowe woos Chinese officials
- Stevens loses Alaska Senate race
- Four days, 11 homicides, several police investigations
- Bonfire built by students caused Montecito fire, sheriff says
- 500 police officers replaced in Tijuana
- Wildfires: Did low water pressure hinder the fight?
- Recall specter hangs over high court as it considers Prop. 8 challenges
- The Koran, punk rock and lots of questions
