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). A small to medium size pale brown, yellow, or green grasshopper. The antennae are sword-shaped (ensiform). A dark stripe extends from the back of the eye across the top of the lateral lobe of the pronotum and onto the forewings (tegmina). A dark stripe may occur on the dorsal median of the pronotum. The hind tibia is pale tan, bluish-green or gray.

Overwinters in the egg stage. Nymphs appear in June, and adults occur from late July or August into October (Capinera and Sechrist 1982, Capinera et al. 2004, Otte 1984, 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). Male body length is 13 mm to 15 mm, and females 18 mm to 20 mm. Wing length usually extending to near the tip of the abdomen but can vary. The forewings have a longitudinal, dark brown stripe, broken into spots in the center and a white stripe below. The outer face of the hind femur has a dark stripe on the upper surface and is not banded.

Can be confused with the Striped Slant-faced Grasshopper (Amphitornus coloradus), Velvet-striped Grasshopper (Eritettix simplex), and the Meadow Grasshopper (Chorthippus curtipennis). Refer to those species for diagnostic comparisons for determining positive identification.

Inhabits shortgrass and mid-grass prairies in areas of sparse vegetation, poor soils and eroded ground (Capinera and Sechrist 1982, Otte 1984, Pfadt 2002, and Vickery and Kevan 1985).

The following comes from Capinera and Sechrist (1982), Capinera et al. (2004), Pfadt (2002), Schell et al. (2005), and Vickery and Kevan (1985). This species is primarily a grass feeder, preferring blue gramma (Bouteloua gracilis) and buffalograss (Munroa squarrosa) which can make up 85 to 100 percent of its diet (consumed by both nymphs and adults). However, nineteen other grass species are known to be consumed in lesser amounts, including Needle-and-Thread (Stipa comata), sand dropseed (Sporobolus cryptandrus), little bluestem (Schizachyrium scoparium), and western wheatgrass (Elymus smithii). In addition, studies have observed this species consuming trace amounts of threadleaf sedge, needleleaf sedge, eight species of forbs, fungi, and arthropod body parts.

No studies of the Obscure Grasshopper’s courtship and mating behavior have been made. Females oviposit their eggs deep into bare soil near its preferred food plants. They lay 8 to 10 eggs in a pod arranged in two columns. The nymphs pass through 5 instars before reaching the adult stage (Capinera and Sechrist 1982, Pfadt 2002, Schell et al. 2005, and Vickery and Kevan 1985).

The Obscure Grasshopper can reach high population densities which makes it a potential pest species on rangeland forage, but its reproductive potential is less than most other grasshopper species considered pests (Capinera and Sechrist 1982, Pfadt 2002, and Schell et al. 2005).