Effect of buckwheat as a flowering border on populations of cucumber beetles and their natural enemies in cucumber and squash

A buckwheat border was planted perpendicular to cucumber and squash rows to attract natural enemies of cucumber beetles. Sticky and modified Malaise traps were used to assess insect populations at incremental distances from the border. The density of Diptera declined from 19.5 insects/sticky card in the border to 2.8 insects/sticky card at 20 m from the border in 1995, and similar declines were seen in 1996. Densities of tachinid flies, Hymenopfera wasps, and the Pennsylvania leatherwing (Chauliognathus pennsylvanicus) also declined as distance from the border increased. Numbers of striped cucumber beetles (Acalymma vittatum Fab.) increased linearly in 1995 but decreased quadratically in 1996, and crop yields were unaffected. (C) 1999 Elsevier Science Ltd. All rights reserved.