Female Mormon cricket
Why do Mormon crickets move en masse? Partly because banding together shields them from predatory birds and mammals, but another reason is to eat each other.
Researchers with the U.S. Department of Agriculture’s Agricultural Research Service have concluded that the crickets’ mass movement is propelled by the nutrient-starved insects nipping at each others’ heels out of hunger and out of fear of being eaten.
In the western United States, Mormon crickets can form bands up to six miles long, pilfering crops and garden plants as they move across the landscape.
Former ARS ecologist Dr. Gregory Sword, who recently accepted a position with the University of Sydney, Australia, studied the insects with researchers Drs. Stephen Simpson of the University of Sydney, Patrick Lorch of Kent State University in Ohio, and Iain Couzin of the University of Oxford in England.
The team discovered that marching crickets were deprived of two dietary necessities, protein and salt, and since the insects are in effect packages of protein and salt, they tend to cannibalize each other. The researchers’ findings could lead to more environmentally friendly tactics for controlling the large swarms of insects, such as natural baits, the ARS reports.