Geographic distribution - east of the Rocky Mountains from North Dakota south to Texas and Mexico and eastward with isolated populations as far as Minnesota, Iowa, Kansas and Oklahoma (Froeschner, 1954). In Colorado, found from the plains to the foothills in the eastern part of the state. Occasionally seen in the hills on open, grassy areas (Gillette, 1904).
Habitat - inhabits the rank vegetation of weedy roadsides, vacant lands and field margins but may move to crops if the rangeland becomes dry. Prefers rocky or gravelly soil in areas of sparse grass and coarse weeds (Ball et al., 1942; Hantsbarger, 1979; Mulkern et al., 1969).
Food habits - forbivorous, preferring coarse forbs. Large amounts of arthropod parts have been found in their crops, indicating that they eat live or dead insects in addition to forbs. Preferred foods are sunflower, blanket flower, ragweed, cotton, lettuce and feverfew (Alexander and Hilliard, 1969; Isely, 1944; Mulkern et al., 1969).
Eggs - pods are large, gourd-shaped and contain about 20 large eggs. Eggs are yellow when deposited but turn dark reddish-brown later with even darker pigmentation at both tips. Average egg length, 10 mm; average diameter, 2.7 mm (Ball et al., 1942: Onsager and Mulkern, 1963).
Adult - large size. The largest species occurring in Colorado. General color is reddish-brown marked with greenish-brown. Body is robust. Antennae are slender. Tegmina are very small and reddish with black spots. Legs are robust with tibiae strongly spined almost the entire length. Each abdominal segment is marked with a row of light dots. Male length, 40 mm; female, 50 to 60 mm. B. magna is flightless (Ball et al., 1942; Hantsbarger, 1979; Scudder, 1876).
Seasonal history - eggs hatch in June. Adult B. magna are present from late June to October (Newton et al., 1954).
Abundance and importance - common throughout eastern Colorado (Gillette, 1904). B. magna is of little importance in grasslands (Mulkern et al., 1969).
B. magna fact sheet from the Field Guide to Common Western Grasshoppers
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Biology of Common Colorado Grasshoppers List
Biology of Common Colorado Grasshoppers
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