Schistocerca alutacea Scudder


Adult female

Common name - Spotted bird grasshopper (Heifer, 1972).

Geographic distribution - the subspecies Schistocerca alutacea lineata is found from Alberta (Canada) and Washington south to Arizona and east to the Dakotas, Michigan, Ohio and Florida. It generally is a Great Plains subspecies. The subspecies S. alutacea shoshone is found from California, Oregon and Washington east to Montana, Nebraska, Oklahoma and Texas (Dirsh, 1974). S. a. shoshone is found along rivers at low elevations in Colorado. S. a. lineata is found in the eastern half of the state.

Colorado Distribution Map

Habitat - S. a. shoshone lives in high herbage near water or in shady moist ravines where shrubs grow. S. a. lineata lives in dry shrubby areas and areas of large weeds (Anderson and Wright, 1952; Hebard, 1928).

Food habits - forbivorous, especially preferring legumes. Amercian licorice, vetch, peavine, milkvetch and the crowns of side-oats grama reportedly are ingested (Anderson and Wright, 1952; Brooks, 1958). In North Dakota, it feeds primarily on leadplant although ragweed and other forbes are eaten. Grasses sometimes are fed upon, especially bluegrass (Mulkern et al. 1964).

Eggs - 50 to 60 eggs are arranged in whorls within each pod. Egg color is yellow turning brownish-red. Average egg length, 6.0 mm; average diameter, 1.2 mm (Onsager and Mulkern, 1963).

Nymph - five instars (Ramsey, 1964).

Adult - large size. S. a. shoshone generally is green with red tibiae. S. a. lineata generally is yellowish brown with purplish, yellow or brown tibiae. Face is nearly vertical. Antennae are slender, and vertex is rounded. Dorsal posterior margin of pronotum is rounded. Pronotum has light yellow spots. A pale yellow streak starts on top of the head and extends along the midline of the back and to the tip of the tegmina. Hind tibiae have long white spurs tipped with black. Subgenital plate of male has a distinct, U-shaped notch at the tip. Male length, 45 mm; female, 60 mm.
S. alutacea is a strong flier often covering 100 yd. or more in a single flight (Ball et al., 1942; Brooks, 1958; Helfer, 1972; Mulkern et al., 1964).
 
Bottom view of thorax Subgenital plate of male

Oviposition - eggs are deposited in small, undisturbed bare sites, pocket gopher mounds or in places where sand has drifted over vegetation (Onsager, 1963).

Seasonal history - adults can be found from mid-July to mid-October (Newton et al., 1954).

Abundance and importance - potentially damaging to forage legumes, trees and shrubs but rarely abundant.
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