Scientists have figured out why so hard to swat a fly


30/08/2008

For two decades, Michael Dickinson, a professor at the California Institute of Technology (Michael Dickinson, California Institute of Technology, Caltech), reporters repeatedly interviewed about his research in the biomechanics of insect flight. But one question journalists pursued him all the time: Why is it so hard to swat a fly? "Now I can finally answer," - said Dickinson.

Using ultra-fast high-quality digital video of the reaction of fruit flies (Drosophila melanogaster) at the approaching fly swatter, Dickinson and his assistant, a graduate student Gwyneth Cruden (Gwyneth Crad), revealed the secret of evasive maneuvering flies. Well before jumping tiny brain calculates the location of flies impending threat, comes up with the plan of salvation, and puts her legs in an optimal position to quickly jump in the opposite direction. All the action takes about 100 milliseconds after the fly "spotted" fly swatter.

According to the scientist, this behavior illustrates how quickly the brain of a fly can handle sensory information to the appropriate motor response.

For example, the video showed that if a fly swatter (during the experiment - black disc diameter of 14 inches) approaches the front at an angle of 50 degrees to fly, standing in the center of a small platform, the fly moves its middle legs forward and tilts the body back, then bend and unbend his legs to jump back. When she sees the approaching threat from the back (the field of view of a fly - almost 360 degrees), the fly moves its middle legs a little. With the threat of the side of the fly does not move its middle legs, but his whole body tilts in the opposite direction from the threat before it will make its redemptive leap.

The scientists also found that while preparing for the jump, fly takes into account its body position at the time when she first saw the threat. First noticed a fly swatter, a fly can be in any position, depending on what she was doing at the time (washed, fed, walked, etc.).

Experiments the researchers showed that the fly somehow ’knows’ whether it should make a big or a small movement to prepare for the subsequent jump and optimum positioning of the body. This means that the fly must be able to integrate visual information from its eyes, speaking from where the threat is approaching, with mechanosensory information from its legs, which tells how we must move to adopt the correct posture before you leap.

The research results provide a new understanding of the nervous system of flies and suggest that the brain of a fly is able to convert the position of the approaching danger in the corresponding position of the legs, and body movement to take off. Now scientists want to find that place in the fly’s brain, where this information is processed.

Dickinson’s study also suggests an optimal method "prihlopyvaniya" fly: it is necessary not just to beat on the fly, and aim a bit forward in the place towards which the fly is scheduled to make his leap, seeing the approaching threat. We will tell you the exciting news from the horse’s mouth.

Original: Caltech.edu


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