Brown-spotted Range Grasshopper - Psoloessa delicatula
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.
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).
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
), and Brunner's Grasshopper
). Refer to these species for diagnostic comparisons.
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:
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(Observations spanning multiple months or years are excluded from time charts)
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).
The Brown-spotted Range Grasshopper is a grass and sedge feeder. Its preferred food plants are blue gramma
), sand dropseed
), brome, Purple Three-awn grass
), needlegrass, wheatgrass, needle-and-thread
), fescue, and sedges (Capinera and Sechrist 1982, Pfadt 2002).
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).
- Literature Cited AboveLegend: View Online Publication
- Brooks, A.R. 1958. Acridoidea of Southern Alberta, Saskatchewan, and Manitoba (Orthoptera). The Canadian Entomologist (Supplement 9) 90:5-92.
- Brust, M.L, W.W. Hoback, and R.J. Wright. 2008. The Grasshoppers of Nebraska. Lincoln, NB: University of Nebraska Extension Service, APHIS.
- Capinera, J.L. and T.S. Sechrist. 1982. Grasshoppers of Colorado: Identification, Biology, and Management. Fort Collins, CO: Colorado State University Experiment Station, Bulletin 584S. 161 p.
- Capinera, J.L., R.D. Scott, and T.J. Walker. 2004. Field Guide to Grasshoppers, Katydids, and Crickets of the United States. Ithaca, NY. Cornell University Press.
- Hebard, M. 1928. The Orthoptera of Montana. Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 80:211-306.
- Helfer, J.R. 1971. How to Know the Grasshoppers, Crickets, Cockroaches, and Their Allies. Revised edition (out of print), Mineola, NY: Dover Publications.
- McDaniel, B. 1987. Grasshoppers of South Dakota. Brookings, SD: South Dakota Agricultural Experiment Station, Bulletin TB 89.
- Otte, Daniel. 1981. The North American Grasshoppers. Volume 1. Acrididae (Gomphocerinae and Acridinae). Harvard University Press. 275 pp.
- Pfadt, R.E. 2002. Field Guide to Common Western Grasshoppers, 3rd edition. Laramie, WY: Wyoming Agricultural Experiment Station, Bulletin 912, modified by S. Schell and S. Schell for electronic publication. Accessed 19 February 2020. http://www.uwyo.edu/entomology/grasshoppers/field-guide/index.html#fieldguidetoc
- Scott, R.D. 2010. Montana Grasshoppers, Katydids, and Crickets A Pictorial Field Guide to the Orthoptera. MagpieMTGraphics, Billings, MT.
- Vickery, V. R. and D. K. M. Kevan. 1985. The grasshopper, crickets, and related insects of Canada and adjacent regions. Biosystematics Research Institute, Ottawa, Ontario. Publication Number 1777. 918 pp.
- Additional ReferencesLegend: View Online Publication
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- Anderson, N.L. 1962. Grasshopper-vegetation relationships on Montana grasslands. Ph.D Dissertation. Bozeman, Montana: Montana State University. 73 p.
- Gillespie, R.L.1992. Dynamics of grasshoppers (Orthoptera: Acrididae) at a rangeland-crop interference. Ph.D. Bozeman, MT: Montana State University. 111 p.
- Hebard, M. 1932. Notes on Montana Orthoptera. Proceedings of the Academy of Natural Sciences of Philadelphia. V. 84. pp 251-257.
- Henry, J.E. 1969. Protozoan and viral pathogens of grasshoppers. Ph.D. Dissertation. Bozeman, MT: Montana State University. 153 p.
- Larson, D.P. 1996. Evaluation of sweep sampling as a method for determining grasshopper community composition on rangeland. M.Sc. Thesis. Bozeman, MT: Montana State University. 92 p.
- Mussgnug, G.L. 1972. The structure and performance of an adult population of Aulocara elliotti (Thomas) (Orthoptera, Acrididae) near Billings, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 97 p.
- Sater, S. 2022. The insects of Sevenmile Creek, a pictorial guide to their diversity and ecology. Undergraduate Thesis. Helena, MT: Carroll College. 242 p.
- Skinner, K.F. 1995. Plant and grasshopper community composition: indicators & interactions across three spatial scales. M.Sc. Thesis. Bozeman, MT: Montana State University. 144 p.
- Wachter, D.H. 1995. The ecology of selected grasshopper species along an elevational gradient. M.Sc. Thesis. Bozeman, Montana: Montana State University. 59 p.
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