ESTIMATION OF ADULT CARABID ABSOLUTE DENSITIES IN A NO-TILL CORN FIELD BY REMOVAL SAMPLING

A removal sampling technique was used and evaluated according to its a ssumptions for estimating the absolute densities of adult ground beetl es (Carabidae). Removal sampling is a method of absolute density estim ation based on the decline in successive catch numbers as individuals are removed from a population. Field arenas were used to isolate sampl ing areas in a no-till corn field, and pitfall traps were installed wi thin the arenas to remove the carabids. A linear regression method was used to calculate the density estimate using the removal sampling dat a. Although the technique provided estimates which were relatively sim ilar to those of mark-release-recapture studies, violations of the ass umptions were observed, and suggestions are made which may improve the accuracy of the estimates and the applicability of the technique.