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Montana Field Guide

Montana Field Guides

Brown-spotted Range Grasshopper - Psoloessa delicatula

Native Species

Global Rank: G5
State Rank: SNR


Agency Status
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General Description
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). This is a small gray, gray-brown to green grasshopper with conspicuous dark body spots and markings. A black marking runs from behind the eye onto the dorsal lateral lobe of the pronotum. Below this marking, the lateral lobe bears an ivory oblique stripe atop a triangular-shaped black stripe and a light narrow oblique stripe angled ventrally. The forewings (tegmina) are long, extending beyond the abdomen tip and marked centrally with 4 to 6 rectangular black spots.

Phenology
This is an early season grasshopper. Overwinters as a third instar nymph. Nymphs begin to appear as early as April. Adults are present from May to July, and lay eggs in early summer. Their numbers decrease during mid-summer but increase as summer eggs hatch in late summer to early autumn and develop through three instars for overwintering (Capinera and Sechrist 1982).

Diagnostic Characteristics
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). The body length to end of forewings is 12 mm to 17 mm for males, and 16 mm to 23 mm for females. Dorsal surface of the pronotum is constricted in the middle and deeply cut by one sulcus (groove). The hind femur is marked with 2 or 3 bands on the upper outer surface, with a distinct central black triangle marking dorsally. The hind tibia is pale gray with orange at the tip.

This species could be confused with the Shasta Slant-faced Grasshopper (Bruneria shastana), and Brunner's Grasshopper (Bruneria brunnea). Refer to these species for diagnostic comparisons.

Species Range
Montana Range Range Descriptions

Native
 


Range Comments
Occurs from the western Canadian provinces southward to northern Mexico, and the Great Plains states west of the Mississippi River, westward to the eastern half of Washington, Oregon and California. In Montana, it has been reported for 10 counties (Hebard 1928, Brooks 1958, Helfer 1971, Otte 1981, Capinera and Sechrist 1982, Vickery and Kevan 1985, Pfadt 2002, Capinera et al. 2004, Brust et al. 2008, Scott 2010).

Observations in Montana Natural Heritage Program Database
Number of Observations: 14

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Inhabits areas of sparsely vegetated short grasses with many bare patches and in dense sagebrush. Does not occur in mountain grasslands but can be found in foothill habitats up to 8,000 feet (Otte 1981, Capinera and Sechrist 1982, Vickery and Kevan 1985, Pfadt 2002, Capinera et al. 2004).

Food Habits
The Brown-spotted Range Grasshopper is a grass and sedge feeder. Its preferred food plants are blue gramma (Bouteloua gracilis), sand dropseed (Sporobolus cryptandrus), cheatgrass (Bromus tectorum), brome, Purple Three-awn grass (Aristida purpurea), needlegrass, wheatgrass, needle-and-thread (Stipa comata), fescue, and sedges (Capinera and Sechrist 1982, Pfadt 2002).

Reproductive Characteristics
A courting male stridulates with 2 to 4 acoustical signals while advancing on a female. When close, he mounts her and attempts to copulate. If successful, the gravid female selects a site of bare ground, deposits 18 eggs, arranged in two columns, per pod over an inch below the surface. Upon hatching, the nymphs pass through 5 instars before reaching the adult stage (Otte 1981, Capinera and Sechrist 1982, Pfadt 2002, and Capinera et al. 2004).

References
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Citation for data on this website:
Brown-spotted Range Grasshopper — Psoloessa delicatula.  Montana Field Guide.  .  Retrieved on , from