Combining Trap Cropping with Companion Planting to Control the Crucifer Flea Beetle

Project Overview

Project Type: Graduate Student
Funds awarded in 2011: $8,270.00
Projected End Date: 12/31/2012
Grant Recipient: Washington State University
Region: Western
State: Washington
Graduate Student:
Principal Investigator:
William Snyder
Washington State University

Annual Reports


  • Vegetables: broccoli, greens (leafy), onions
  • Additional Plants: herbs, ornamentals


  • Crop Production: intercropping
  • Education and Training: extension, on-farm/ranch research, workshop
  • Pest Management: cultural control, integrated pest management, trap crops
  • Production Systems: organic agriculture

    Proposal abstract:

    The crucifer flea beetle, Phyllotreta cruciferae, is a major pest of Brassica crops in the Pacific Northwest. Many growers rely on these crops as a major component of mixed-vegetable production, and flea beetle damage lowers marketable yields. In previous work we found that “trap crops,” which draw beetles out of the marketable crop, are effective in partially protecting broccoli from flea beetle damage. Here, we propose to examine companion plants intercropped with broccoli as an additional, complementary flea beetle management option. Our hypothesis is that marketable companion crops planted within the protection target will further hinder flea beetles’ ability to chemically or visually locate their host plants. Thus a companion crop may provide an additional incentive for flea beetles to choose the trap crop rather than the broccoli, working synergistically to improve flea beetle control.

    Project objectives from proposal:

    We propose to examine the use of companion plantings to control crucifer flea beetle, alone and in combination with trap crops. We predict that companion plantings will interrupt host-finding by flea beetles and other broccoli pests and enhance densities of beneficial predators and parasitoids.

    Our objectives are to:

    1) Determine the most effective companion crop species to discourage flea beetle colonization of broccoli and improve marketable yield.

    2) Examine how the companion plants will affect colonization by other broccoli pests and beneficial insects (and spiders).

    3) Examine the combination of companion planting and trap cropping for flea beetle control.

    4) Distribute what we learn to growers through an outreach program, including a substantial extension presence, along with field days and other outreach strategies that maximize coverage.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.