Vegetation Structure and Microhabitat Selection in Grasshoppers (Orthoptera, Acrididae)

Microhabitat selection in relation to vegetation structure and general aspect is des- cribed for grasshoppers from an arid grassland in western Texas. Comparisons of microhabitat use are made among species at each site and between sites as well as between entire assemblages of species (lumped) for the two sites in order to assess the role of biotic interactions in the determi- nation of the patterns. Grasshoppers do not inhabit microhabitats in a random fashion and very definite preferences are observed for most species. Also, the number and type of microhabitat occupied by grass- hoppers varies according to species. Use of structural microhabitat by all species is observed to be in the same proportion as that in which it occurs in the habitat even though individual species generally use only a restricted range of microhabitats. The use of structural habitat between Mara- thon and Sul Ross Mountain (for the entire assemblage in each case) is statistically indistingui- shable. Distributions of niche breadths for all species at a site do not differ between Marathon and Sul Ross Mountain and distributions of niche breadth do not differ between subfamilies. How- ever, individual species found at both Marathon and Sul Ross Mountain may occupy different microhabitats from one site to the next. The notion that interactions among species are responsi- ble for patterns of microhabitat use is discussed.