Summary: Mormon crickets are among some of the more harmful species of insects in the United States, with the potential to cause significant damage to rangelands and crops. Several options are available for the population control of these pests.
The Mormon cricket, also sometimes called a long-horned meadow grasshopper, is actually not a true cricket or grasshopper at all, but a shield-backed katydid. However, katydids, grasshoppers and crickets are all close relatives in the insect world. Reaching up to about two inches in length, this wingless katydid is generally dark brown or black in color and can be found across Western North America. Mormon crickets are also known for their very long antennae and their widely spaced œgoggle-eyes.
While not all species of katydids are considered to be major pests, the Mormon cricket has been known to cause severe damage to crops and rangeland in the United States. The Mormon cricket actually earned its name after nearly decimating the crops of the first Mormons settlers in Utah in 1848. A monument now stands in Temple Square in Salt Lake City, commemorating the destruction of the plague of Mormon crickets by large flocks of seagulls.
Another Mormon cricket outbreak in 1937 is reported to have caused nearly half a million dollars worth of crop damage in Montana. At the high point of this particular plague, nearly 20 million acres spanning 11 different states were infested with this goggle-eyed pest. Mormon cricket outbreaks can last for many years and densities can reach up to 100 insects per square yard.
Mormon crickets have been known to feed on up to 400 different species of vegetation, which includes wild mustard, alfalfa, sugar beets and small grains. These insects do not generally breed in cultivated croplands, but they can and do migrate there after they reach maturity. In fact, cultivated crops, such as wheat and barley tend to be some of their favorite meals. Although they do not fly, Mormon crickets manage to cover up to one half-mile per day just by crawling and hopping along. Not only do they feed on leaves and stems in their wake, but they also damage plant growth and seed production, which means a more significant impact on rangelands and livestock feeding.
While Mormon crickets are not always a cause for concern, an outbreak still has the potential to cause major economic damage. Population fluctuations are thought to relate closely to variations in the weather, which often allows for natural control. Like the outbreak in Salt Lake City in 1848, modern-day Mormon crickets are also kept in check by species of gulls, hawks and rodents, for whom the insect makes a tasty meal.
Like some species of locusts, Mormon crickets can cause problems when their populations are allowed to grow out of control. However, in regular numbers, they can be an essential part of the local ecosystem, performing important functions and providing food for other predatory species. When populations threaten to grow too large, several control techniques can be used, including land management, prescribed burning and chemical pest control methods. Often, controlling such populations becomes a Federal issue as individual landowners and growers cannot afford to take care of these outbreaks on their own.