Montana Field Guide

The following comes from Hebard (1928), Brooks (1958), Helfer (1971), Otte (1981), Capinera and Sechrist (1982), Vickery and Kevan (1985), McDaniel (1987), Pfadt (2002), Capinera et al. (2004), and Scott (2010). This is a medium sized grasshopper with an oversized head bearing a dark streak below the eye to the top of the mandibles. The dorsal area of the pronotum is dark with a light X-like marking. The lateral side of the pronotum has a large black marking. The outer face of the hind femur is cream colored with 3 conspicuous black stripes on the upper surface continuing onto the inner surface. Hind tibia is blue.

Overwinters in the egg stage. Nymphs hatch in early June and continue to occur into August. Adults occur from mid-July to mid- October (Capinera et al. 2004, Capinera and Sechrist 1982, Pfadt 2002, Scott 2010, and Vickery and Kevan 1985).

The following is taken from Hebard (1928), Brooks (1958), Helfer (1971), Otte (1981), Capinera and Sechrist (1982), Vickery and Kevan (1985), McDaniel (1987), Pfadt (2002), Capinera et al. (2004), and Scott (2010). The body length of males is 15 to 17 mm and females 20 to 25 mm. Females are significantly larger than males in this species. The female 8th ventral abdominal segment’s posterior margin has two deep clefts. The wings (tegmina) usually do not reach the tip of the abdomen, although there are some rare individuals collected with wings extending beyond the abdominal tip.

The White-crossed Grasshopper is similar to the Big-headed Grasshopper (Aulocara eliotti). A quick separation can be made by comparing the shapes of the female 8th ventral segment’s posterior margins. A. elliotti lacks deep clefts in the margin. See that species for other diagnostic characters.

Found most frequently in shortgrass, mixed-grass and bunchgrass prairies where western wheatgrass (Elymus smithii), needle-and-thread (Stipa comata), and blue gramma (Bouteloua gracilis) are abundant (Capinera et al. 2004, Capinera and Sechrist 1982, Otte 1984, Pfadt 2002, and Vickery and Kevan 1985).

Feeds almost exclusively on grasses and sedges, favoring western wheatgrass (Elymus smithii), and needleleaf sedge (Carex duriuscula). A study revealed a difference in diets between males and females. The males ingested much larger amounts of short grass species and sedges, whereas the females consumed larger amounts of mid grasses such as western wheatgrass (Pfadt 2002, and Schell et al. 2005).

Males court females with conspicuous visual signals with the hind femur. No observations of copulation have been recorded. Females select a small bare soil area (1 to 6 square inches) surrounded by blue gramma (Bouteloua gracilis) or other short grass to deposit her eggs to a depth of about one-eighth to three-quarters of an inch. Each pod contains 9 to 11 eggs. Upon hatching the White-crossed Grasshopper passes through 4 instars in males, 5 instars in females. Males require a minimum of 30 days to become adults, females require 42 days to reach the adult stage. There is one generation per year (Capinera and Sechrist 1982, Otte 1984, Pfadt 2002, and Vickery and Kevan 1985).

This species can be destructive of rangelands. It is usually sub-dominate in outbreak assemblages with the Big-headed Grasshopper (Aulocara eliotti). It rarely reaches high population densities, and usually does not last more than one year (Pfadt 2002, and Schell et al. 2005).