RESEARCHES ON NORTH AMERICAN ACRIDI1D/E 



By ALBERT P. MORSE, 

 Research Assistant, Carnegie Institution of Washington. 



INTRODUCTION. 



The work on which report is here made was done under a 

 grant from the Carnegie Institution of Washington and was directed 

 toward the acquisition of facts of faunal, biological, and morpho- 

 logical value concerning the Acridian fauna of the southeastern 

 United States, a portion of the country hitherto largely unexplored 

 with reference to this group of insects. 



A study of the general topography, based, when possible, on 

 the maps of the United States Geological Survey, led to a plan of 

 operations in accordance with variations in the life history of differ- 

 ent species. This plan involved an examination of the different life 

 zones of the region at as early and as late dates as practicable, in 

 order to secure earlier and later maturing forms, since it is impos- 

 sible, with our present knowledge, to distinguish many of the 

 species with certainty save in the adult state. 



About 60 widely separated localities were examined in 68 days 

 during a trip of 3,000 miles through the region under inspection. 

 Approximately 6,000 specimens were secured in this time, repre- 

 senting 90 species of Acridiidse (of which one-sixth were new to 

 science), together with notes of great biological interest. 



Many important data relating to the biology and distribution of 

 the group were secured ; but in some cases, owing to the character of 

 the trip a rapid reconnaissance over a wide extent of territory for 

 the purpose of securing general information the results should be 

 regarded as tentative until further detailed studies can be made. 



This report includes a general account of the investigation and 

 a statement of the results secured ; the data on which the general- 

 ized statements are based, in the form of an annotated list of the 

 species taken, with locality, habitat, and date of capture ; brief 

 notes on the geographical and zonal distribution of the genera of 

 North American Acridiidse ; and contributions to locust biology in 



