Montana Field Guide

The following is taken from Hebard (1928), Brooks (1958), Vickery and Kevan (1985), Pfadt (2002), Capinera and Sechrist (1982), Capinera et al. (2004), and Scott (2010). This small to medium sized species is perhaps one of the most colorful of the Melanoplus genera, especially with its bright orange inner face of the hind femur and light blue tibia. The outer face of the hind femur is tan and crossed transversely with three dark bars. The middle bar is usually chevron shaped.

Hatching and nymphs occur from mid-May to mid-June. Adults present from late June through October.

Taken from Hebard (1928), Brooks (1958), Vickery and Kevan (1985), Pfadt (2002), Capinera et al. (2004), Capinera and Sechrist (1982), and Scott (2010). The body length to end of forewings is 19 to 21 mm for males, and females is 22 to 24 mm. Wings (tegmina) extend to or slightly beyond the abdominal tip and have a row of alternating light and dark square spots centrally. The cercus of the male genitalia is diagnostic: it is unusually large and triangular, appearing ear-like or fan shaped.

Can be confused with the Nevada Sage Grasshopper (M. rugglesi), to which it is related. The two species can be separated by comparing the shape of the males genital cerci, which does not taper to a point at the tip in M. rugglesi (Capinera et al. 2004).

The Occidental Grasshopper inhabits nearly all the grassland/prairie types in the Great Plains, with highest densities observed in mixed grass prairie. This species also occurs in open grassy areas at mountain elevations to >12,000 feet above timberline (Vickery and Kevan 1985, Capinera et al. 2004, Capinera and Sechrist 1982, Pfadt 2002, and Scott 2010).

The following comes from Pfadt (2002), Capinera et al. (2004), and Capinera and Sechrist (1982). A polyphagous grasshopper, favoring the leaves of forbs but also consumes substantial amounts of grasses, moss, roots, seeds and dying or dead arthropods. In mixed-grass prairie studies, food contents consisted of 70 to 90 percent forbs, 8 to 15 percent grasses and 1 to 10 percent arthropod parts. Favored plants include scarlet globemallow (Sphaeralcea coccinea), wild buckwheat, milkvetch, blue grama (Bouteloua gracilis), needle-and-thread (Stipa comata), and western wheatgrass (Elymus smithii).

The following is taken from Pfadt (2002), Capinera et al. (2004), and Vickery and Kevan (1985). This species overwinters in the egg stage. Nymphs pass through 5 instars before becoming adults in 40 to 45 days. Females begin laying eggs within about 2 weeks after fledging to the adult stage. Eggs are laid in bare spots. She deposits 8 to 10 eggs per pod arranged in two columns. Adults remain in the same habitat in which the eggs hatch and nymphs develop.

The Occidental Grasshopper rarely reaches outbreak pest population densities but can contribute significantly to total grasshopper outbreak densities in concert with other pest species. This species is a common member among prairie grasshopper assemblages and can be a crop pest (Pfadt 2002, and Schell et al. 2005).