Pitfall traps were placed at the
end of 4 permanently marked transects within the sites sampled. Five scent plates
were placed evenly from end to end along the transects, thus providing 20 samples
per site. The transects were parallel to each other, 25m apart, and in the prairies
40m long and in the savannas 50m long.
Insects were sampled 7 to 9 times throughout the 1992 growing season. All specimens were manually sorted and identified to species (89.8% of specimens) or morphospecies within known genera or families.
Species biovolume, an index of biomass, was calculated as the average product of length (from tip of head to top of abdomen), width (maximum width of body or head) and thickness (maximum thickness of body or head) for 5 specimens in the oldest life stage for each Orthoptera species. Even though body size increases greatly during development, this method seemed justified since most species (84%) only occurred as adults in the samples taken. To minimize counting a species twice, all larvae were examined by outside experts and, if they might have been the same species as an adult insect, they were counted as a single species.
Voucher specimens were deposited in the Cedar Creek insect collection.