10 MONTANA EXPERIMENT STATION BULLETIN 474 



As the young of some grasshopper species developed, changes 

 in their feeding habits were noted. In the earher stages of their 

 development some were found feeding mainly on dry plant ma- 

 terials found on the ground. As they developed, green food-plants 

 were included more and more in their diet. Some species con- 

 sumed large quantities of dry plant materials throughout their 

 life while others never included dry plant materials in their diet. 

 After some species reach the adult stage in their development 

 very little feeding can be detected. 



1950 MONTANA RANGE PLANT STUDIES 



The area studied comprised approximately two sections of 

 range land on the OW ranch, 22 miles southeast of Decker, Mon- 

 tana. The distribution of vegetation in this region is determined 

 by variations of topography and soils. A resistant sandstone stra- 

 tum caps the higher plateaus. The dominant vegetation on the 

 sandy loam soils, derived from the weathering of the underlying 

 sandstone, is big sagebrush ( Artemesia tridentata). Sparse stands 

 of ponderosa pine (Pinus ponderosa) occur along the edges of these 

 mesas and along the ravines which cut into them. The steep slopes 

 below the pines are thinly populated with big sagebrush, snake 

 weed (Gutierrezia sarothrae) , yucca (Yucca glauca), blue grama 

 grass (Bouteloua gracilis), side oats grama (Bouteloua curtipen- 

 dula), little bluestem (Andropogon scoparius), mat muhly (Muh- 

 lenhergia squarrosa) , June grass (Koeleria cristata), red three-awn 

 (Aristida longiseta) , and various herbaceous plants such as wild 

 alfalfa (Psoralea tenuiflora), prairie clover (PetalosteTnon pur- 

 pureus), sulphur flower (Eriogonum sp.), and pussy toes (Anten- 

 naria sp.j. 



Deep, well-drained alluvial fans which slope gently downward 

 from the steeper eroded slopes support a dominant stand of big 

 sagebrush with June grass, needle-and-thread (Stipa comata), and 

 blue grama. 



Hills and benches of lower elevation are capped with beds 

 of scoria. Practically pure stands of bluebunch wheatgrass (Agro- 

 pyron spicatura) are present on gravelly sands which have weath- 

 ered from the scoria parent material on top of the hills and benches 

 and on steep north-facing slopes. Sandy loam soils on the top of 

 the benches and on the gentler slopes support a dominant stand 

 of needle-and-thread and western wheatgrass (Agropyron svfiithii) 

 with some June grass, feather bunch grass (Stipa viridula), and 

 blue grama. Gravelly soils on steep west-facing and south-facing 

 slopes are populated with little bluestem, side oats grama, red 

 three-awn, mat muhly, blue grama, snake weed, and yucca. Heavy 

 clay soils in the swales and valley bottoms are dominated by 

 western wheatgrass. On lighter soils around the periphery of 



