Farming for Native Bees

Project Overview

Project Type: Research and Education
Funds awarded in 2014: $247,649.48
Projected End Date: 03/31/2018
Grant Recipient: UC Berkeley
Region: Western
State: California
Principal Investigator:

Annual Reports


  • Fruits: apples, apricots, avocados, berries (other), cherries, citrus, melons, peaches, pears, plums, berries (strawberries), general tree fruits
  • Vegetables: artichokes, beans, beets, broccoli, carrots, cauliflower, cucurbits, greens (leafy), parsnips, peas (culinary), peppers, sweet corn, tomatoes
  • Additional Plants: herbs, native plants, ornamentals
  • Animals: bees


  • Crop Production: cover crops, fallow
  • Education and Training: demonstration, display, extension, farmer to farmer, focus group, on-farm/ranch research, workshop, youth education, technical assistance
  • Farm Business Management: budgets/cost and returns, feasibility study, agricultural finance, value added
  • Natural Resources/Environment: biodiversity, habitat enhancement, hedgerows, wildlife
  • Production Systems: holistic management, organic agriculture
  • Sustainable Communities: new business opportunities, partnerships, employment opportunities, sustainability measures


    In early 2014, in partnership with Western SARE, Dr. Gordon Frankie (PI) began work on "Farming for Native Bees", an innovative project that constructs  and monitors high quality native bee habitats on avocado farms in Ventura Co. and vicinity, Southern California.  The following report describes  objectives and breakthroughs accomplished during the third grant period (Dec. 2016-Dec. 2017).  This includes:

    1. Standardized pan traps and aerial (net) collections were used to monitor bees and other visitors at 6 sites in 3 large avocado farms.  In contrast to the previous drought years, monitoring yielded substantial new visitor information, owing to greatly increased rainfall during winter of 2016/ 2017, which stimulated plant growth and visitor populations. Drought returned again in 2017/2018 winter, which impacted plants and flower visitors somewhat. 
    2. Intensive visitor frequency counts and collections from avocado flowers yielded 15 identified native bee species and several undetermined hover fly and wasp species.  These are the first documented records of non-Apis mellifera visitors to avocado flowers in California.  This work leads to an estimate of 30-35 potential pollinating insects visiting avocado flowers in this area.
    3. Installation of one additional acre of bee-attractive perennials at the Elwood Canyon Ranch in Goleta.  (one additional acre was also added to the Butler Ranch in 2016).
    4. Increased interest and cooperation form owners/mangers of the 3 farms in the form of offering more labor to help maintain bee habitat gardens, and offering more space to increase sizes of bee gardens; offers to buy bee plants as well.
    5. Increased outreach to other SoCal avocado growers on the form of 2 separate field demonstrations of bee habitat constructions.  Outreach done in collaboration with Ben Faber, UC Cooperative Extension, Ventura Co.
    6. General outreach to diverse audiences across CA through numerous presentations, conferences, and a large submitted peer-reviewed publication on the model study (Brentwood bees in NorCal) for the Ventura project in SoCal.
    7. Continuation of Pollinator Habitat Advisor (PHA) pilot project with a UC Berkeley student. Results indicate that the position calls for a horticulturalist and an entomologist working together. 
    8. Completion of a report on the socioeconomics of farmers cooperating on farming for native bee projects in Brentwood and Ventura Co. and vicinity (available upon request).
    9. Flip-card booklet on common native bees of California (and farms) was published by the UC-ANR Division of the University of California, Davis, CA (see attached advertisement).  A copy is available upon request.

    Project objectives:


    Native Bee Monitoring:

    We continued to conduct a standardized bee monitoring program in 2017 at all 6 study sites on the 3 SoCal farms.  At each farm (or ranch as they are called locally) there is a control site and a treatment site, where the constructed bee gardens are located.  Control and treatment sites at each ranch are separated by considerable distance.  Results of monitoring in 2017 produced increased collections of bees over previous drought years (as reported in last year's progress report).  These collections also produced 12 native bee species (additional species recorded in 2018) and several hover fly and wasp species that were visiting avocado flowers.  The new flower host records are the first documented non-Apis insect visitors to avocado flowers in California.  Casual observations of a few insects have been mentioned in the past by growers, but this was the first time that bee collections were made, identified to species and curated.  Fly and wasp species are currently being prepared for identification.

    Bee Garden Expansions:  Once the new visitor identifications were confirmed, we began installing more perennial plants in the treatment gardens, which were known to attract target native bee species and at least some fly and wasp visitors.  This gardening work started in late spring and was continued through Dec. 2017.  Further, we also announced this progress to each owner, and in response they offered additional space for more plantings.  In the case of the Jim Lloyd Butler Ranch, we have nearly doubled the size of the original bee garden and have plans to double it again in 2018, with the urging and financial support of the owner.  The Elwood Canyon Ranch in Goleta is in the process of being doubled in size (in 2018), and the Thille Ranch will be doubled as well in 2018, with the help of the owner.

    Garden Maintenance:

    Each of the 3 gardens has required periodic maintenance in the form of weeding, pruning, and some replacements or additions of new plants to keep the pollen and nectar flowing.  At each ranch owners have offered help by providing workers to assistance to the PI, who supervises all maintenance.  This action is part of the original collaboration agreement made with each owner.  An added value to this activity is the opportunity to continually interact with owners and managers of each property to share results and respond to questions.

    Curation of Collected Insects:

    Monitoring at control and treatment sites produced a wealth of insects and host floral records in 2017, owing to the strong rainy season of 2016/ 2017.  Each insect was labeled accordingly and curated into collections maintained at the Urban Bee Lab at UC Berkeley.  All bees have been identified to species by Jaime Pawelek and to a limited extent by Robbin Thorp at UC Davis.  Bee species were databased, which allowed for examining long-term patterns since monitoring began in 2014.  The examination also allowed us to assess the effects of the drought years.  This evaluation will continue with the planned monitoring of 2018 and hopefully in 2019, and we also expect that our case history will contribute to ongoing discussions on climate change, the effects of which are evident from our work.


    We completed a report on the socioeconomic analysis of native bees and farmers's responses to the concept of incorporating native bees into their farming operations (available upon request).  It is considered preliminary as it did not include the discovery of the several non-Apis visitors to avocado flowers that has stimulated some farmers.  It is clear that we will need to do more interview work in the future as interest on our results has picked up considerably with the new 2017 discoveries.


    Building on the 3 power point presentations to avocado growers in 2016, I gave 2 separate field demonstrations of our work at the Jim Lloyd Butler Ranch in summer, 2017.  The demos were arranged by Ben Faber, UC Coop Extension.  During the demos, I was able to share results of our non-Apis visitors finding, which were well received.  Approximately 100 growers from across the state attended these events.

    Findings of our work are scheduled to be presented at an international conference on avocados that will be held in Istanbul Turkey in August, 2018.  Ben Faber will present the paper that will feature our work.


    The concept of the PHA is to develop a pilot program to train a person whose speciality would be working with farmers to develop bee habitat gardens within their agricultural fields to encourage native bees to visit crop flowers and thus provide crop pollination services to supplement honey bee pollination.  We had considered using the University of California extension service, but upon inquiry they are too over worked with all their other responsibilities to take on this special work.

    We have been working with one UC Berkeley student to evaluate the feasibility of the approach. We learned that farmers are interested in making use of native bees, but they don't know or have experience in setting up the bee habitat gardens. Further, we now believe that the position actually calls for 2 professionals; a horticulturalist and an entomologist. The issue of market demand for such a service needs further investigation. 


    There have been a few problems encountered in 2017, but we have dealt with each of them as they arose, and have also depended greatly on the help of Ben Faber who guided us through some of the divergences, most of which were temporary.  We have been greatly motivated by the discoveries mentioned above and this is taking us into new questions and territories.

    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.