Comparing the accuracy and effectiveness of three sampling methods of grasshoppers (Orthoptera: Acrididae) in a western Oklahoma grassland

Accurate characterization of grasshopper community composition is a critical but often challenging component of grassland ecology. Abundance and density of grasshoppers is most commonly determined by using two methods simultaneously: counting the number of grasshoppers present in a number of 0.1 m² rings and collecting sweep-net samples.  If ten 0.1 m² rings are used, the density of grasshoppers per m² can be determined by adding up the total number of grasshoppers observed.  After identifying the species of grasshoppers present in the sweep-net samples, by comparing the percentages of each species with the total grasshopper density collected from the rings, grasshopper species density can be determined.  Data from both traditional techniques are presented here, along with data from a novel collecting method that was developed and performed simultaneously.  The time it takes a collector to acquire twenty grasshopper individuals “by any means necessary” (BAMN) was recorded as a comparative sampling technique.  In this novel approach the collector works within a specified area (“arena”) abandoning efforts after twenty minutes has been reached.  Preliminary data show that it takes a collector longer amounts of time to collect twenty grasshoppers in areas where grasshopper density is low.  Comparative grasshopper species abundance and species density data for all three sampling methods are presented here.  Additionally, pitfall traps measuring activity density of all ground-dwelling arthropods in this Western Oklahoma grassland have caught a number of grasshoppers.  Preliminary data do not show a relationship between grasshopper activity density as determined by the pitfall traps versus density rings.