Mormon Cricket

The Mormon cricket is not actually a cricket, but a katydid. They get very big, 3" long. They can black, brown, red, green or purplish. They lack wings and travel by hopping and crawling. They swarm sometimes in large numbers and are cannibals, eating the squashed remains of each other while trying to cross a road. There isn't much they don't eat.
They were eaten by the Native Americans, but don't have a specific predator. Anything that eats them gets full quick!

A concise account from Wikipedia on the background of their name:
After Brigham Young led the first band of Latter-day Saints into what is now Salt Lake City, Utah, the pioneers had the good fortune of a relatively mild winter. Although late frosts in April and May decimated some of the crops, th... read moree Mormons seemed to be well on their way to self-sufficiency. Unfortunately, swarms of insects appeared in late May.

These insects, now called "Mormon crickets" because of this incident, are not true crickets, but instead belong to the katydid family. Having ornamental wings, they are unable to fly, but instead travel in huge devouring hoards. Mormon crickets eat all plant material in their path, but they also cannibalize any insects that die on the way. They're known to cyclically swarm in some areas of the Mountain West, especially in Utah and Nevada, but these bugs understandably terrified the pioneers. Stomping on the pests did not dissuade them from entering farms. Indeed, other crickets would advance to eat the remains of their brothers. Mormons, prolific journal writers, often cast this disaster in Biblical terms like the 8th plague of locusts.

According to some pioneers accounts, legions of seagulls appeared by June 9, 1848. Many letters and diaries recount that these birds, native to the Great Salt Lake, ate mass quantities of crickets, drank some water, regurgitated, and continued eating more crickets. Ornithologists don't regard this as particularly unusual because the seagulls around the Great Salt Lake often eat insects in the adjacent valleys, but some pioneers saw the gulls' arrival as a miracle. The traditional story is that the seagulls annihilated the insects, ensuring the survival of some 4,000 Mormons who had traveled to Utah. For this reason, Seagull Monument was erected and the California gull is the state bird of Utah.