Population Density, Dispersion, and Dispersal Estimates for Scarites substriatus , Pterostichus chalcites , and Harpalus pennsylvanicus (Carabidae) in an Iowa Cornfield 1

Abstract
Population density, dispersion, and dispersal were determined for the adult carabids, Pterostichus chalcites Say, Scarites substriatus Haldeman, and Harpalus pennsylvanicus DeGeer, inhabiting an Iowa cornfield during the summer of 1975. Population density estimates were calculated by a mark and recapture technique. Maximum population densities for P. chalcites , S. substriatus , and H. pennsylvanicus were 0.20 · m −2 , 0.08 · m −2 , and 0.39 · m −2 , respectively. All three species had aggregated dispersion patterns, which were probably due to differences in the environment. Dispersal for P. chalcites and S. substriatus averaged 8.5 and 12.2 m/day, respectively, and individuals of these species were captured an average of 14 days after initial release. H. pennsylvanicus may have dispersed more readily than the other two species and evidently moved into the field from field borders during early to mid-August.

This publication has 2 references indexed in Scilit: