Assessing the effects of non-honeybee insects on pollination in diversified organic farms

Assessing the effects of non-honeybee insects on pollination in diversified organic farms

Summary

Our project is assessing the impact of non-bee insect pollinators on organic crop production in small scale, diversified farming systems in western Washington. Non-bee pollinators such as flies, butterflies, moths, and beetles often visit blooming flowers and may play significant, but often underappreciated, impacts on crop pollination. Determining the role of non-bee pollinators on crop pollination would aid farmers understand the importance of conserving this group of insects on their farms. During the first year of this Western SARE project, we are identifying the plant biodiversity on each of 30 farms in western Washington, making visual observations of floral visitations by non-bee pollinators, and collecting insects from flowers on each of these 30 farms. Our overall goal is to determine the pollination impact of non-bee pollinators in these systems. In the second year of the project, we will use data on which flowers are being most often visited, and by which species most often, to design and conduct experiments involving dominant groups of non-bee pollinators and honey bees. These experiments will allow us to determine whether the presence of certain non-bee pollinators affects the behavior of honey bees in the field. All of our work is being conducted with the cooperation of a network of grower-collaborators. We are using social and multimedia formats to disseminate information about non-bee pollinators to this group of stakeholders in addition to the general public.

Objectives/Performance Targets

Our objectives for this project were as follows: (1) Characterize communities of non-bee insects on diversified organic farms and their direct contribution to crop pollination; (2) Examine whether non-bee insects indirectly affect crop pollination by bees; and (3) Educate farmers and the public on the role of non-bee pollinators in sustainable farming.

Within these objectives, we had the following performance targets:

Objective 1:

(A) Sample and characterize communities of non-bee insects on 24 farms

(B) Measure the pollination efficiency by non-bees

Objective 2:

(A) Quantify indirect effects of non-bees on pollination by bees

Objective 3:

(A) Develop educational materials for growers

(B) Conduct a series of field days attended by over 100 farmers

(C) Create a project website that includes downloadable materials and a podcast. Our goal is to have over 1,000 downloads of podcasts on pollinators by the end of the project

Accomplishments/Milestones

We have achieved the following during the past reporting period:

Objective 1: Sample and characterize communities of non-bee insects

(A) We sampled communities of non-bee pollinators on each of our 30 farms. This sampling will be repeated in the second year of the project. In 2016 the data collected includes 30 hours of field-observations of non-bee floral visitations (1 hour per site), 30 hours collecting non-bees from flowers in the field, and 60 hours characterizing the floral biodiversity at each of 30 farms. All of the non-bee insects observed to visit flowers were collected using nets and returned to the laboratory. We have conducted initial processing of these samples (cleaning them and ensuring their long term preservation) and we are in the process of identifying all the insects to species. These data will be matched up with data on the flowers visited by non-bee insects. Once this is done we will have the ability to characterize the non-bee pollinator community and the structure of the plant-pollinator network. We expect data from 2016 to be processed by early 2017.

(B) Our original goal was to measure pollination efficiency by non-bee insects in the field. However, this has proven difficult because non-bee insects are difficult (if not impossible) to identify in the field beyond the family level, and these insects visit flowers less frequently than bees. However, we have indirect data on pollination services provided by non-bee insects from our sampling data collected on the plant-pollinator network. Moreover, from our experiments that are planned in 2017 we will gather data on pollination efficiency of some of the major groups of non-bee insects, and syrphid flies in particular, as this group dominates on most of our farms.

Objective 2: Quantify indirect effects of non-bees on pollination by bees

This objective was not slated to be performed until 2017, and we are still on track to meet this goal. We are using data from Objective 1 on the major groups of non-bee insects observed on our farms to design experiments to investigate how these species affect pollination by bees, and vice versa. As we have a robust dataset on non-bee pollinators, which has already allowed us to identify some major groups of importance, as well as the types of flowers where bees and non-bee pollinators co-occur, we are well positioned to complete this objective as planned.

Objective 3: Conduct extension related to non-bee pollinators

(A) In 2016 PI Olsson participated in 3 field days focused on pollinators in diversified farming systems. Each field day consisted of a 4-hour program that focused on methods growers can use to monitor pollinators (bees and non-bees) on the farm, techniques for pollinator identification; we also covered current research in pollinator ecology, pollinator declines, and pollinator conservation.  These field days attracted over 70 participants. During the first field day, the primary demographic of participants were organic farming students at The Evergreen State College in Olympia, WA. The primary demographic at the second and third field days were organic farmers in northwestern Washington.

(B) In addition to the field days described above, we conducted additional talks about pollinators to school groups, master gardeners, and Seattle Tilth.

(C) We submitted a guide to monitoring and identifying pollinators to the Washington State University extension publication center for publication. This extension guide includes extensive information on both bees and non-bee pollinators. The document is currently in revision, and we expect it to be published in early 2017 prior to the start of the intensive field season. This document will be disseminated widely to growers through our websites and network of collaborators.

(D) In June 2016, we hosted Gary Nabhan during National Pollinator Week at Town Hall Seattle, in cooperation with the Northwest Pollinator Initiative, and there were over 100 attendees from the Seattle metropolitan area. The primary demographic at this event were urban gardeners from within Seattle, and diversified organic farmers from the greater Seattle area, and who primarily sell their produce at markets and to restaurants in Seattle. Two smaller subsets of attendees at this event were University of Washington faculty and students, and local policy makers. This talk focused broadly on strategies to increase the sustainability of farming systems, with a particular focus on pollinator conservation.

(E) We created a website, www.whatsthebuzzresearch.com. This site has received a total of 384 unique visitors, and is visited on average 26 times per month, since its incarnation. There are currently 73 subscribers to the RSS feed, which will automatically update those subscribers when new content is available. We have published 3 episodes of the What’s The Buzz podcast, and have recorded interviews for 2 more episodes. Researcher Olsson plans to release 3 episodes before the end of Spring 2017, including interviews with expert researchers that were recorded during the International Congress on Entomology in September 2016. These recorded interviews will provide content for further episodes of the podcast and entries to the blog, to be released over the remainder of 2016. Based on trends seen previously, we anticipate downloads of content to increase with each subsequent podcast episode and blog post.

Impacts and Contributions/Outcomes

As detailed earlier, we are in the midst of work on Objectives 1 and 2, and the impacts of these Objectives will not be fully realized until later in 2017 when the data is fully collected and analyzed. However, we anticipate the major impacts of these objectives to be: (1) a greater understanding of the role of non-bee pollinators on diversified organic farms; (2) increased adoption of strategies for non-bee pollinator conservation on farms throughout the Pacific Northwest; and (3) an understanding of the interactive role of bees and non-bee insects on crop pollination. We expect these results will have significant impact for both academic audiences and growers/home gardeners.

Our work on Objective 3 is already generating significant impacts. Between the field days, National Pollinator Week, and website, we have made over 500 unique contact points with the general public. Many of these individuals have remained invested in our project by continuing to support our research or contributing to a citizen science initiative on native pollinators that was launched in 2016. We have created a diverse set of outputs, including websites, field days/presentations, and extension guides to target individuals from a wide spectrum of backgrounds.

Once it is published, we expect that our pollinator monitoring guide will significantly add to the number of people being reached by this project.

Collaborators: