14 DAY TRIAL // For many years, scientists have been trying to figure out what is it that drives locust swarms in their devastating migrations. When this happens, crops and other vegetation is at tremendous risk, as the insects appear to have an insatiable appetite. But, despite experts' best efforts, no clear solutions to the problem have been found. Now, after complex mathematical calculations, a team of investigators says that finding a clear-cut answer will most likely never happen.
The group determined that the factors influencing swarm mechanics and motions are completely random, and cannot therefore be placed in any computer model. A study detailing the new theory has already been accepted for publication, in an upcoming issue of the esteemed scientific journal Physical Review E. The major conclusion is that ever-changing interactions of random factors is what ultimately dictates the motions and directions of locust swarms, as well as the extent to which they decimate vegetation on any given tract of land.
“These swarms are driven by intrinsic dynamics. In all practical terms, predicting when a swarm is going to change direction is going to be impossible,” says Princeton University biologist Iain Couzin, a member of the team that conducted the recent investigation. But the work may nonetheless contain the seeds of some interesting pest-control applications, the experts say. A better understanding of locust swarms could inform farmers on where to place pesticides and other chemicals in their fields, ahead of an incoming invasion. Chances of this approach succeeding are not very significant, but the benefits of success far outweigh the risks.
The investigators add that the behavior of locusts is also peculiar because no one can ever know when an accumulation of random factors will reach the tipping point, and cause a change. Studies of the physics behind locust swarms proved that the collective motions change properties in a manner similar to how magnetic particles switch their properties while in clumps subjected at high temperatures. “It’s impossible to know when the next switch will happen. Still, we have a little bit more understanding on how these perturbations are produced, and we hope that in the long run we can apply this practically,” says Consejo Superior de Investigaciones Científicas expert Carlos Escudero, quoted by Wired.