"In repeated experiments, we found that within two days, 50 percent to 60 percent of insects transplanted out of the band were dead because something ate them," he said. "On the other hand, we found no deaths during the same period among the crickets we monitored that stayed with the band."
That individuals removed from the group suffered gory deaths was clear from partially chewed transmitters the scientists recovered, often with body parts still attached, Lorch said. Researchers retrieved several devices from trees and burrows. Two were lost entirely and, presumably because Mormon crickets can't fly, carried off a long way by birds and out of radio receiver range.
"What this new work appears to show is that even though being part of the band has its own costs -- such as greater competition for food and cannibalism of injured crickets ?overall, there's a clear benefit to band members," Lorch said. "Predation occurs anyway, but any given individual is far better protected than it would be if it were on its own."
The research, supported by the USDA, is part of a larger study designed to learn whether scientists can predict and possibly change the path of massive insect bands, he said.
"In the United States nowadays, Mormon crickets just cost farmers and others a lot of money, but in parts of Africa and elsewhere, locusts can cause widespread famine because they consume crops, and the people there sometimes have nothing else to eat."