Earth Science News  





. What's Bugging Locusts. It Could Be They're Hungry - For Each Other

Desert locusts usually feed on vegetation, but individual locusts have been observed to feed on other live locusts or cadavers.
by Kitta MacPherson
Princeton NJ (SPX) May 13, 2008
Since ancient times, locust plagues have been viewed as one of the most spectacular events in nature. In seemingly spontaneous fashion, as many as 10 billion critters can suddenly swarm the air and carpet the ground, blazing destructive paths that bring starvation and economic ruin.

What makes them do it?

A team of scientists led by Iain Couzin of Princeton University and including colleagues at the University of Oxford and the University of Sydney believes it may finally have an answer to this enduring mystery.

"Cannibalism," said Couzin, an assistant professor of ecology and evolutionary biology at Princeton.

Writing in the May 8 online edition of Current Biology, Couzin and colleagues say that the collective motion of locusts is driven by "cannibalistic interactions."

"Cannibalism is rife within marching bands of locusts," said Couzin. Desert locusts usually feed on vegetation, but individual locusts have been observed to feed on other live locusts or cadavers. This behavior and its effect upon the group, however, have not previously been studied.

"No one knew until now that cannibalistic interactions are directly responsible for the collective motion exhibited by these bands," added Couzin, whose graduate student, Sepideh Bazazi, is the lead author on the paper.

In zoology, cannibalism is defined as occurring when any species consumes members of its own kind.

Young locusts are pressed to eat others when the food supply necessary for supporting the population starts to dwindle. Starved for essential nutrients such as protein and salt, young locust "nymphs" will nip at each other. Those under siege react by running from the aggressors.

Others get jittery and simply seek to put space between them and any locust approaching from behind. That's how one aggressive interaction can lead to another and collectively start a vast migration, Couzin said.

And the activity intensifies, as the biting and ominous approach of others increases both the propensity to move and the forward momentum of individual locusts.

The researchers reached their conclusion by studying immature, flightless locusts. They developed computerized motion analysis to automatically track the insects marching in an enclosed arena.

In nature, Couzin said, these locust nymphs can gather in large mobile groups called bands. They can stretch over tens of miles, devouring vegetation as they march. They inevitably precede the flying swarms of adult locusts.

"Once they take flight, locust control is extremely expensive and ineffective," Couzin said. "So understanding when, where and why the bands of juvenile locusts form is crucial for controlling locust populations."

Through history, locusts have invaded up to one-fifth of the Earth's surface, he said. They have contributed to major humanitarian crises in areas such as Darfur and Niger.

Besides having practical applications, understanding the movement of locusts also is part of a growing inquiry by scientists into an area known as group dynamics. With locusts, researchers have been seeking to understand how the group seems to move with the synchronized perfection of the Rockettes when there is no centralized leader and individuals can barely see beyond a few neighbors on either side.

Animal groups such as flocks of birds, schools of fish and swarms of insects frequently exhibit such complex and coordinated collective motion and present a great opportunity to understand how local interactions can lead to vast collective behavior, the scientists said.

Community
Email This Article
Comment On This Article

Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
Princeton University
Darwin Today At TerraDaily.com




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Platypus Genome Sequenced, Unlocking Secrets Of Evolution
Cold Spring Harbor NY (SPX) May 13, 2008
By any account, the platypus is an odd creature. It's got a broad, rubbery bill that brings to mind a duck....but it swims more like a beaver....yet it lays eggs and can inject poisonous venom, like a reptile. No wonder it was considered an elaborate hoax by scientists who examined the first specimen pelt shipped to England from the colony of New South Wales in 1799.

.
Get Our Free Newsletters Via Email
  



  • Myanmar cyclone's youngest survivors face trauma: UN
  • Transport, communications in chaos after China quake
  • UN to Myanmar: 'Act now or more lives will be lost'
  • No news from county at epicentre of China quake: Xinhua

  • McCain splits with Bush on climate change
  • Key Climate Sensor Restored To NPOESS
  • Cleaner air to worsen droughts in Amazon: study
  • Australia needs years of heavy rainfall to crack drought: experts

  • USGS Awards Satellite Imagery Contracts: Enhancing Access To Users
  • Bluesky Launches 3D Computer Models Of Britain's Cities
  • Cartosat 2a Puts The World In High Resolution For Indian Government
  • NASA Nasa Satellite Captures Image Of Cyclone Nargis Flooding In Myanmar

  • China faces 7.3 million tonne LPG shortfall in 2010: report
  • Analysis: Turks eye carrying Kazakh oil
  • Higher fuel prices may mean less pollution
  • E-Fuel Unveils World's First Home Ethanol System

  • Bacteria epidemic at Madrid hospital claimed 18 lives: report
  • China virus death toll hits 30 as number of infections soars
  • China urges authorities to step up education of deadly disease
  • Doctors punished in China for mishandling deadly virus outbreak: Xinhua

  • Rainfall, rivers predict fish biodiversity
  • Platypus Genome Sequenced, Unlocking Secrets Of Evolution
  • What's Bugging Locusts. It Could Be They're Hungry - For Each Other
  • UNEP sounds alarm over decline in migratory birds

  • Chinese leader seeks Japanese help on environment
  • Toxic ponds kill ducks in Canada
  • Researchers Look To Make Environmentally Friendly Plastics
  • Europe Spends Nearly Twice As Much As US On Nanotech Risk Research

  • Nearly One-Third Of US Parents Don't Know What To Expect Of Infants
  • Walker's World: Bye-bye boomers
  • United We Stand: When Cooperation Butts Heads With Competition
  • Stonehenge excavation may alter history

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement