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What’s Bugging Locusts ? It Could Be They’re Hungry — For Each Other

ScienceDaily (May 9, 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 ? In a word, cannibalism. Credit : iStockphoto/Ruvan Boshoff

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.

Story Source

The above story is based on materials provided by Princeton University.

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