Differential Grasshopper

Melanoplus differentialis — the differential grasshopper — is one of the most economically important crop-pest grasshoppers in North America and one of about 250 species in genus Melanoplus (the dominant grasshopper genus of North American grasslands). The species is widespread across the central and southern US from Wisconsin and Michigan south through Texas and west to California, with the densest populations in the Great Plains agricultural regions. Adults are 3-4 cm body length (females larger than males), bright YELLOW with bold black markings on the body and the species' diagnostic feature: a HERRINGBONE PATTERN of black markings on the hind femora (the 'thigh' segments of the jumping hind legs). The herringbone pattern is the most reliable field-ID feature distinguishing the differential grasshopper from other Melanoplus species. The species is one of the dominant CROP-PEST GRASSHOPPERS in North American agriculture. Outbreak populations occur cyclically across the Great Plains and central US (typically 2-5 year cycles), with severe outbreaks causing massive damage to corn, sorghum, alfalfa, wheat, vegetable crops, and ornamental plants. Historic outbreaks include the 1930s Dust Bowl outbreaks (which contributed substantially to the agricultural collapse of the central US during the dust bowl years) and major modern outbreaks (the 2010 Wyoming outbreak alone caused tens of millions of dollars in agricultural losses, with grasshopper densities reaching 50-100 individuals per square meter across thousands of square kilometers of rangeland). The species is the focus of major USDA Agricultural Research Service grasshopper monitoring programs across the central US. Females lay eggs in soil pods (clusters of 50-150 eggs deposited in undisturbed grassland or fence-row soil) that overwinter and hatch in spring as the next generation of nymphs. Outbreak years are correlated with specific weather patterns (dry spring conditions favoring nymph survival) and habitat disruption (overgrazing and drought-stressed grasslands favor population buildup). The species feeds on a wide range of grasses and forbs and switches to crop plants when wild forage is depleted in outbreak years. The species is harmless to humans (no venom, no bite, no sting) but is one of the most economically important agricultural pests in North America.