Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Locusts’ Built-In ‘Surface Analysis’ Ability Directs Them to Fly Overland

12.08.2005


Closeup of locust in tree. (Photo by Asaph Rivlin)


Swarms of millions of locusts have, since Biblical times and until our very own day, been considered a “plague” of major proportions, with the creatures destroying every growing thing in their path.

Until now, it was thought that the directions of these swarms were predominantly directed by prevailing winds. Now, Hebrew University of Jerusalem scientists have shown that a physiological trait of these grasshoppers – namely their polarization vision -- provides them with a built-in source of “surface analysis” – a discovery that could pave the way for efforts to effectively combat this periodic scourge by controlling their natural inclination to fly over land rather than water.

The desert locusts, known scientifically as Schistocerca gregaria, are able to swarm for great distances and in numbers measuring in the millions. During the locust invasion of November 2004 in Israel, it appeared that a swarm came in an easterly direction over Sinai up to the Gulf of Eilat, then turned northward without crossing the water. Only when the swarm reached the northern tip of the gulf did some of them turn again east in the direction of Aqaba and other areas of Jordan, as well as straight north over southern Israel.



This observation led to examination by scientists of the Hebrew University of Jerusalem Department of Evolution, Systematics and Ecology and the Interuniversity Institute for Marine Sciences in Eilat to examine how the locusts were able to identify the gulf water and knew not to fly over it. The research focused on the ability of the locusts to identify polarized light. This is a trait which is lacking in humans but exists among other species, such as fish and insects.

The research was conducted by Dr. Nadav Shashar, who is considered a leading world expert on polarized sight, working with two students, Shai Sabah and Noa Aharoni. The research was published in a recent issue of the journal of the British Royal Society, Biology Letters, as well as in the science news sections of the journals Science and Nature.

“In order to examine if the locusts are using polarized light in determining their flight path, we examined individual locusts’ reactions in situations in which polarized and non-polarized light was reflected from various surfaces. We were able to prove that the locusts avoided flying over areas which were reflecting polarized light -- for example from mirrors or plastic surfaces.”

The sea reflects polarized light much more than dry land (which reflects mainly diffused, non-polarized light), enabling a distinction to be made between the two.

“When the locusts are presented with a situation of choice between surfaces reflecting either polarized or diffused light, they exercise their preference to fly over the (dry land) area of diffused light,” said Dr. Shashar. This is a survival instinct, since if they flew over a body of water, the locusts would be deprived of both nourishment and a place to land and rest.

This research, said Dr. Shashar, could be important in providing information that would be useful in developing means for “deceiving” the locusts and deterring them from flying over agricultural lands and causing the great damage that ensues.

One way of doing so might be through more extensive use of plastic sheeting as shields to create the reflection of the polarized light that the locusts avoid.

Jerry Barach | alfa
Further information:
http://www.huji.ac.il

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>