Featured Research

from universities, journals, and other organizations

Fruit Flies Show Surprising Sophistication In Locating Food Source

Date:
February 19, 2008
Source:
University of California - Los Angeles
Summary:
A tiny fruit fly, with a brain smaller than a poppy seed, combines massive amounts of information from its sense of smell and vision, then transforms these sensory signals into stable and flexible flight behavior that leads them to a food source. Understanding the integration of these sensory cues could be relevant to developing smarter robotic drones.

To a fruit fly, a piece of rotting fruit or the food in your picnic basket is a little slice of heaven. It's where the tiny animal--not much more than a speck on your fingertip can find food and a mate, the two passions of its short, two-month lifespan.

Related Articles


But the odor plume of a food source can be very slight, subject to the vagaries of wind and other weather, in a world that looms large to this tiny bug. Yet the fly is uncanny in finding a meal. How? By using more than just its sense of smell.

UCLA researchers show that tiny Drosophila, with a brain smaller than a poppy seed, combines massive amounts of information from its sense of smell and vision, then transforms these sensory signals into stable and flexible flight behavior that leads them to a food source. Understanding the integration of these sensory cues could be relevant to developing smarter robotic drones.

"Essentially we show how vision allows flies to navigate odors," said Mark Frye, an assistant professor in the Department of Physiological Science, and a member of the UCLA Brain Research Institute. He is coauthor of the paper, along with Brian Duistermars, a Ph.D. candidate and member of Frye's lab.

The conundrum is this: fruit flies have 700 times lower visual spatial resolution than humans, and five times fewer olfactory receptor types. Yet their ability to find smelly things in visual landscapes as diverse as forests, deserts, and backyard patios would suggest a behavioral performance greater than might be predicted by the sum of its sensory inputs.

Frye and Duistermars found that flies stay the odor course by combining sensory information. They designed a "virtual plume simulator" in which a fly is tethered, but free to steer into and out of a plume of vinegar odor (nectar to a fruit fly). At the same time, a cylinder around the fly displayed a variety of background images, meant to roughly mimic the images the flies might encounter in the real world--blades of grass, say, or twigs on a tree.

Flies' keen senses allow for some incredible maneuvers. During flight, a male housefly chasing a female can make turns within 40 milliseconds--less than the blink of an eye. When they're hungry, flies track weak scents of food to far-flung places. Both feats depend on the tight integration of sight and smell.

Normally in free flight, a fly's path is characterized by segments of straight flight interspersed with transient "spikes" called saccades where they veer left and right.

On the cylinder, the researchers displayed a visual backdrop of equally spaced, high-contrast vertical stripes, and then periodically switched the vinegar plume between 0 and 180 degrees within the circular arena. Then they tracked the fly's heading. Under these conditions, the animal periodically encounters the plume by steering into it. Upon plume contact, the fly performed fewer saccades, presumably because it is honing in and following the plume. Yet the saccades were not altogether absent, Frye notes, an apparent attempt on the fly's part to "constantly seek the sweet spot--the strongest scent--of the plume."

To examine the visual influence on odor-tracking accuracy, the researchers changed the visual backdrop. They alternated a sequence of three visual treatments including high-contrast stripes, uniform grayscale, and a second high-contrast treatment. Each fly started within the vinegar plume and was exposed to the three visual stimuli at 20 second intervals. When the striped and high-contrast panoramas appeared, the flies were able to maintain their heading into the plume. But when the flat, featureless grayscale was displayed, the flies steered out of the plume and began generating saccades. Even though they occasionally would reencounter the plume within the grayscale visual panorama, they were unable to remain there until the high-contrast pattern reappeared, at which point accurate plume tracking resumed.

Frye said this shows the flies are using the backdrop as physical markers to keep track, along with their olfactory sense, of where the plume is. Such "crossmodal integration" at the behavioral and cellular level, said Frye, represents a functional adaptation for distinguishing and responding to critically important features of a complex sensory environment.

Frye noted that a fruit fly's brain only has approximately 200,000 neurons, compared to the billions of neurons in a human brain. "Yet a fruit fly casually outperforms the most sophisticated robots that humans can engineer," he said. "The research in our lab seeks to understand the mechanisms with which a tiny nervous system controls the vastly complex biomechanics of flying. In doing so, we hope to advance our understanding of sensory neurobiology and also help to develop smarter robots."

This research was published online in the journal Current Biology February 14.


Story Source:

The above story is based on materials provided by University of California - Los Angeles. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Los Angeles. "Fruit Flies Show Surprising Sophistication In Locating Food Source." ScienceDaily. ScienceDaily, 19 February 2008. <www.sciencedaily.com/releases/2008/02/080214130341.htm>.
University of California - Los Angeles. (2008, February 19). Fruit Flies Show Surprising Sophistication In Locating Food Source. ScienceDaily. Retrieved December 17, 2014 from www.sciencedaily.com/releases/2008/02/080214130341.htm
University of California - Los Angeles. "Fruit Flies Show Surprising Sophistication In Locating Food Source." ScienceDaily. www.sciencedaily.com/releases/2008/02/080214130341.htm (accessed December 17, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, December 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) has the story. Video provided by Buzz60
Powered by NewsLook.com
Rover Finds More Clues About Possible Life On Mars

Rover Finds More Clues About Possible Life On Mars

Newsy (Dec. 17, 2014) NASA's Curiosity rover detected methane on Mars and organic compounds on the surface, but it doesn't quite prove there was life ... yet. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins