Investigating the Effect of Hedgerows to Enhance Natural Biological Control

Project Overview

Project Type: Graduate Student
Funds awarded in 2006: $10,000.00
Projected End Date: 12/31/2008
Region: Western
State: California
Graduate Student:

Annual Reports


  • Vegetables: broccoli, cauliflower, cucurbits, greens (leafy)


  • Education and Training: networking, on-farm/ranch research
  • Natural Resources/Environment: habitat enhancement, hedgerows
  • Pest Management: biological control, prevention
  • Sustainable Communities: sustainability measures

    Proposal abstract:

    Developing ecological approaches to reduce the pressure of crop pests is a critical component of integrated pest management. A promising approach is conservation biological control, where naturally occurring arthropod predator and parasitoid populations are enhanced through the provision of habitat on and surrounding the farm. Producers in the Central Coast of California are beginning to establish hedgerows in the borders of their fields to improve the habitat for beneficial insects. While increasing botanical diversity in farms should result in an increase in arthropod diversity, key to improving biological control services is enhancing the right type of insects. The quality, quantity, and accessibility of food resources vary from one plant to another and feeding preferences of natural enemies can change throughout the year. Additionally, pest populations may also increase with added habitat. Three main areas are addressed in this research project: 1) monitoring key arthropod natural enemies and pests attracted to hedgerow vegetation, 2) tracing the movement of these indicator arthropods into adjacent vegetable fields, and 3) measuring the rate of biological control in the vegetable fields. Research findings will be widely disseminated through on-farm workshops and publications to help inform on-farm habitat management decisions and conservation biological control practices.

    Project objectives from proposal:

    The objectives of this research are 1) to investigate the effectiveness of hedgerows in the Central Coast of California for biological control in vegetable cropping systems and 2) to make practical recommendations to producers on semi-natural habitat management for pest management in mixed-vegetable systems.

    Performance Targets:
    June 2006 - October 2006:
    (1) Monitor (through monthly vacuum samples) key natural enemies and pests at six hedgerow plant species within 5 different hedgerows.
    (2) Determine the effect of hedgerows on parasitism rates in vegetable fields.
    (3) Trace insect movment from hedgerows into adjacent vegetable fields with a fluorescent pigment external marker.

    November 2006 - April 2007:
    (1) Continue to process vacuum samples (identify insects, preserve specimens, and record data)
    (2) Identify nsect specimens on sticky traps and determine the proportion of insects with the fluorescent marker.
    (3) Analyze the results from all three experiments.

    May 2007 - Ocotber 2007
    (1) Determine the effect of hedgerows on parasitism rates in vegetable fields (second year of data).
    (2) Trace insect movment from hedgerows into adjacent vegetable fields with a fluorescent pigment external marker (second year of data).

    November 2007 - June 2008
    (1) Analyze the results from these two experiments.
    (2) Organize and hold workshops in the area to disseminate results.
    (3) Publish results in academic journals and the Center for Agroecology and Sustainable Food Systems' Research Briefs.
    (4) Make results available to public via a website.

    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.