Mormon crickets are large, flightless insects known for dramatic mass movements. Despite their name, they possess unique characteristics and a compelling history. Found widely in western North America, their occasional population booms highlight their ecological impact.
Their True Identity
Despite their name, Mormon crickets are not true crickets. They are a species of shield-backed katydid, scientifically known as Anabrus simplex. True crickets have short, thick antennae and rub their wings for sound. Katydids, including the Mormon cricket, have long, slender antennae, often longer than their body. Katydids also rub specialized wing structures for sound, and females often have a distinct, sword-like ovipositor.
Physical Characteristics and Life Cycle
Mormon crickets are substantial insects, measuring 1.5 to 2.5 inches. Coloration varies widely, from black and brown to green, yellow, or reddish hues. They lack functional wings, meaning they cannot fly but can jump short distances. Their robust bodies feature a prominent, shield-like pronotal shield.
Their life cycle begins with eggs laid deep in the soil during late summer or fall. Eggs overwinter, hatching the following spring when soil temperatures rise. Newly emerged nymphs are small and wingless, undergoing multiple molts (instars) as they grow. Each instar sheds its exoskeleton. After 60 to 90 days, often by early summer, nymphs mature into adults, ready to reproduce.
The Origin of Their Unique Name
The name “Mormon cricket” stems from a historical event involving early settlers of the Church of Jesus Christ of Latter-day Saints in Utah Territory. In 1848, vast swarms descended upon pioneer agricultural fields in the Salt Lake Valley. The crickets consumed crops like wheat, barley, and corn, threatening widespread famine.
As crops faced destruction, large flocks of California gulls reportedly arrived, feeding on crickets and saving much of the harvest. Settlers widely regarded this event as a miraculous intervention, solidifying the insect’s association with Mormon pioneers. The “miracle of the gulls” became a foundational narrative, linking the insects to the early Latter-day Saint community.
Understanding Their Swarming Behavior
Mormon crickets are known for dramatic swarming behavior involving millions of individuals. Mass movements are triggered by high population densities and favorable environmental conditions, like drought followed by moisture for egg hatching and vegetation growth. As populations increase, they aggregate and march in cohesive bands.
Swarms can extend for miles, with crickets moving relentlessly in one direction, often covering several miles daily. Their sheer numbers can be overwhelming, leading to ecological and agricultural impacts. They devour crops, rangeland, and gardens, causing economic losses. Their presence on roads creates slick, hazardous conditions, as crushed crickets make surfaces slippery and dangerous.