GRASSHOPPERS IX RELATION TO PLANT ASSOCIATIONS. 149 



numerous. Grasshopper species of ruderal dry grassland are, in 

 approximate descending order of importance : Melanophts atlanis, 

 Camnula pelludica, M. bivittatus, Dissosteira Carolina, Arphia 

 pseudonietana. All of these species, with the possible exception of 

 the last, are more abundant in ruderal than in native vegetation. 



Sparsely Vegetated or Bare Soil. The condition of bare soil is 

 much more frequent, in humid climates, as a result of disturbance. 

 Plowed fields and constantly trampled paths and roads are the 

 commonest areas of bare soil, and these furnish suitable habitats 

 for those species which normally rest on bare soil, not on the 

 plants. The (Edipodince are of this habit to a large extent. 

 The character of the soil is important for oviposition, and though 

 the bare soil grasshoppers are more or less migratory, certain of 

 them are found associated with particular types of soil. Hart 

 gives the soil-preferences for a number of the Melanopli in a 

 sand region in Illinois ('07: 214, 215). It is to be remembered 

 that bare soil as a habitat is not sufficient; nearby vegetation 

 is necessary, and in this region is always present. Where exten- 

 sive areas of bare soil occur, grasshoppers are very rare except at 

 the border. The insects are conspicuous in bare places, as roads, 

 but are more abundant in the interspaces between plants, in 

 open growths. Areas of bare soil differ from the sparsely 

 vegetated areas merely in degree, and are really the same kind of 

 habitat. In the region studied considerable bare soil is exposed 

 along the beach, but in the aspen association roads are the typical 

 areas of bare and sparsely-grown soil, as also in the hardwood 

 district. Interstitial grasshoppers which are conspicuous in bare 

 soil are: Dissosteira Carolina, Arphia pseudonietana, Circotettix 

 verruculatus , Spharagemon bolli, and Hippiscus tuberculatus. 

 Those of open grassland, frequently found on bare soil of inter- 

 stices, and less frequently on bare soil of roads, are: Camnula 

 pellucida, Melanoplus atlanis, M. bivittatus, M. angustipennis. 



Meadow Associations.- Ruderal meadows and swales, like the 

 native marsh and littoral associations, are variable in character. 

 Probably the most common type is the bluegrass-white clover 

 meadow. It is found in wet pastures and along boggy roads; 

 it forms a very low, dense carpet, resembling a closely trimmed 

 lawn, and probably always depends on constant cropping of 



