Cordillacris occipitalis

Adults are tan and gray, slim, and medium-sized. Antennae are tan or pale and slightly ensiform. A conspicuous brown stripe runs from behind the middle of the compound eye onto the lateral lobe of the pronotum. The pronotum has a low but distinct median carina cut once behind the middle, with low lateral carinae highlighted in ivory. Wings are long, extending to the end of the abdomen or slightly beyond; tegmina are spotted brown with an ivory streak above the base of the hindleg. Hind tibiae are pale orange. Nymphs have a strongly slanted face, ensiform antennae brown with light tan anterior edges, a conspicuous brown stripe running from behind the compound eye along the side of the head and body, and a wide tan stripe with brown spots on the dorsum.

Grasslands including mixedgrass, shortgrass, desert, and bunchgrass prairies. Reaches greatest abundance in sandy loam soils of the mixedgrass prairie. Does not inhabit tallgrass prairie or dense stands of mid grasses.

Western North America. Recorded in California, Colorado, Nebraska, Nevada, and New Mexico.

Early-hatching species. Nymphs emerge five to seven days before bigheaded grasshopper nymphs. Hatching period lasts four weeks. Adults appear in July in northern mixedgrass and shortgrass prairies.

Feeds on green leaves of grasses. Diet includes at least 15 grass species and four sedge species, including blue grama, needleandthread, western wheatgrass, sand dropseed, downy brome, threadleaf sedge, and needleleaf sedge. Rarely consumes forbs or ground litter.

Eggs are laid in the ground at shallow depth (top one-half inch of soil) and develop to embryonic stage 19 by fall, entering diapause. Development resumes in spring. Nymphal period estimated at 22.5 days by calculation, though 36-41 days is considered more realistic. Adults appear in July. Females oviposit in bare ground or at base of grass clumps, forming vertical pods containing two to three eggs.

Spends night resting on vegetation or ground. Basks sides perpendicular to sun rays for one to two hours after sunrise, beginning normal activities when air temperature reaches 70°F. Feeds by climbing plants and chewing leaves in a head-down position, holding the leaf with front tarsi. Evasive flights are straight, silent, low (2-4 inches), and short (2-4 feet), usually with the wind. When temperatures exceed 90°F air and 120°F soil, adults climb small shrubs to rest in shade.

Primary consumer in grassland ecosystems. Can reach densities of 40 per square yard in outbreak conditions, though more commonly 1-5 per square yard. Contributes to grassland herbivory pressure, particularly in sandy loam soils where it may dominate assemblages.

Pest of rangeland grasses, particularly in mixedgrass prairie with sandy loam soils. At outbreak densities, causes economic damage to forage. Individual impact estimated at half that of the bigheaded grasshopper due to smaller size.

• Cordillacris crenulataSimilar size and habitat preference, but C. crenulata has crenulate or scalloped brown stripes on tegmina rather than spotted pattern, and hatches three to four weeks later.
• Aulocara elliotti (bigheaded grasshopper)Similar feeding habits and habitat, but larger (twice the weight), with different color pattern and head shape.

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Crenulatewinged Grasshopper
• Spottedwinged Grasshopper
• Grasshoppers of Colorado
• Grasshoppers of Colorado
• Grasshoppers of Colorado
• Species Records and Accounts