Mormon Cricket

Mormon crickets can grow to almost 8 cm (3 inches) in length. Individuals vary in coloration: the overall color may be black, brown, red, purple or green. The pronotum, the dorsal "shield" above the prothorax, covers vestigial wings); in some specimens it bears colored markings. The abdomen may have a striped appearance. Like many Tettigoniidae, females have a long ovipositor, which should not be mistaken for a stinger. As is characteristic of Tettigoniidae, the antennae are long and filamentous. They are in general longer than the head plus body, though the ovipositor extends to beyond the ends of the antennae. As also is the case in swarming locusts, high population densities of swarming Mormon crickets cause them to undergo changes in morphology and coloration: solitaria, individuals in the solitary phase, typically have green or purple coloration, while swarming individuals, gregaria, are often black, brown or red.

Mormon cricket eggs hatch mostly in the spring after they are laid, although in some areas eggs may take as many as five years to hatch. Hatching begins when soil temperatures reach 4 °C (40 °F). The nymphs pass through seven instars before reaching the adult stage, typically taking 60 to 90 days. Breeding begins within 10 to 14 days of reaching the adult stage. The male passes to the female a large spermatophore which can be up to 27% of his body weight. The spermatophore is mostly food for the female to consume but also contains sperm to fertilize her eggs. This nuptial gift causes swarming-phase females to compete for males, a behavior not seen in solitary-phase females. The female lays her eggs by thrusting her long ovipositor deep into the soil. Each female can lay over one hundred eggs, with individual eggs having the appearance of a grain of rice with a gray to purplish color.