Cordillacris occipitalis (Thomas)

Adult male Adult female

Common name - Spotted wing grasshopper.

Geographic distribution - from Alberta, Saskatchewan and Manitoba (Canada) south to Texas, New Mexico, Arizona, California and Oregon (Otte, 1981). Its Colorado range is the eastern plains and eastern mountain valleys (Hebard, 1929).

Colorado Distribution Map

Habitat - eroded areas, sandy areas, river valleys and areas of scant, dry, low vegetation (Brooks, 1958; Hebard, 1928).

Food habits - a graminivorous species that prefers succulent blue grama, moderately wilted needleandthread and severely wilted western wheatgrass. It also consumes prairie sandreed grass, threeawn and sand dropseed (Kumar et al., 1976; Ueckert and Hansen, 1971).

Eggs - three whitish eggs are deposited in each pod (Onsager, 1963).

Nymph - five instars (Scoggan and Brusven, 1972).

Adult - small size. General color is dull, yellowish-brown. Face is slanted back slightly. Vertex is rounded. Antennae are slender. Dorsal posterior margin of pronotum is rounded. Lateral brown stripes extend from the vertex of the head, through the eyes, widen across the head and extend along the pronotum without curving downward. Tegmina are opaque with a row of brown spots. Wings are clear. Hind femora are buff with a brown stripe on the outer face. Hind tibiae are light orange. Male length, 15 mm; female, 19 mm (Ball et al., 1942; Brusven, 1967; Helfer, 1972).
Tegmen Pronotum (Top view)

Oviposition - occurs on such bare sites as pocket gopher mounds and eroded areas (Onsager, 1963).

Seasonal history - eggs overwinter (Scoggan, 1972). Adults are present from late June to early September (Newton et al., 1954).

Abundance and importance - often common (Helfer, 1972). Along with several other species, it can form a complex that is damaging to sagebrush grasslands (Scoggan and Brusven, 1972).

C. occipitalis fact sheet from the Field Guide to Common Western Grasshoppers
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Biology of Common Colorado Grasshoppers
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