Spatial and behavioral responses of crucifer flea beetle (Phyllotreta cruciferae) to a trap crop scheme in northern Idaho

The crucifer flea beetle, Phyllotreta cruciferae, is a widespread pest of cultivated plants in the genus Brassica. In this study we investigate the effectiveness of one of its host plants, Pak Choy (Brassica rapa), as a potential trap crop for managing the crucifer flea beetle in small-scale organic production of broccoli (Brassica oleraceae). We examine the distribution of the beetle across varying spatial arrangements of the trap and target crop to determine the configuration and distance at which the trap crop affords the greatest protection to broccoli over the course of the growing season. In addition we present focal observations of the behavior of the flea beetle in the field and in small greenhouse experiments with trap and target crop plants in order to understand the mechanisms driving their response to trap crop deployment geometry and to assist in future management efforts.