Managing Solitary Cavity Nesting Bees for Cane Fruit in Oregon

Managing Solitary Cavity Nesting Bees for Cane Fruit in Oregon

Summary

We have had a steady increase in native bees, particularly the Oregon berry bee(Osmia aglaia and the blue orchard bee O. lignaria) on our berry farm since 2008, despite two very cold, wet springs that reduced berry production. Fields with introduced native pollinators have had better pollination than fields without introduced native bees. Technical problems have continued to plague our attempts to get a webcam functioning that will show the native bees actively nesting and foraging in our fields, but we have a plan that should be successful in the spring of 2012. Outreach efforts have begun with the publication of a short article on our project for the Oregon Raspberry and Blackberry Commission in their spring 2011 newsletter. In addition, this SARE-funded project has stimulated an additional cooperative effort with the Xerces Society and the USDA NRCS to do plantings of native species that will provide additional forage for native bee species, hopefully contributing to even greater increases in native bee populations on the farm. Plans are under way for a presentation at the annual meeting of the ORBC meeting in December 2011, and we hope to participate in a field day with the Xerces Society as early as June 2012 to showcase the various native pollinator projects on our farm.

Objectives/Performance Targets

This project has three main objectives:

1. To develop populations of native bees on our berry farm in Corbett, OR, particularly the Oregon berry bee, Osmia aglaia, as well as other native species that may contribute to berry pollination.

2. To determine the feasibility and cost of using a webcam to get feedback from experts to help us manage populations of native bees during berry bloom.

3. To increase awareness by berry growers and others of the existence and diversity of native bees and of simple ways to preserve and manage this resource. In addition, we hope that the webcam will allow growers not included directly in the research to become involved and learn about berry pollination by native bees in real time.

Accomplishments/Milestones

1. Our first objective, to develop populations of native solitary bees on our berry farm in Corbett, OR, particularly the Oregon berry bee, Osmia aglaia, has been successful. Populations of the Oregon berry bee, O. aglaia, have increased from a population of about 1,500 in 2008 to about 21,700 at the beginning of the 2011 season. We have also started managing the native Blue Orchard Bees, Osmia lignaria, which we hope will pollinate black raspberries early in the season, before O. aglaia is active. In 2010, we collected about 280 female O. lignaria cocoons from nests in our raspberry fields. An additional 400 females of O. lignaria from the Portland area were introduced to our farm in spring 2011.

In 2011 the bees started to emerge and were put in the field on May 10. However, the weather was cold and wet until mid-June, so bloom was even later than in spring 2010. O. lignaria were active in spite of the cold weather, and we observed some of them foraging on black raspberries. We thought that the orchard bees did a good job of pollinating the Black Raspberries, and the Osmia aglaia performed so-so.

Technical Advisor Karen Strickler and her husband visited our farm on June 16 and 17 when the black raspberries were past peak bloom and marionberry was starting to bloom. She found honeybees, bumblebees and O. aglaia visiting the berries. O. aglaia probably started foraging and nesting that week for the first time, when temperatures started to warm. O. lignaria had already completed quite a few nests by that time. Karen and her husband looked for O. lignaria on raspberry but did not see them, so there is still some question about how much both species of Osmia contribute to raspberry pollination. They also found a nest of a small carpenter bee, Ceratina sp., in dead raspberry canes. This is another species that could be managed to some extent by providing pithy stems for the bees to nest in.

The wet weather resulted in yield losses on our raspberry production due to freeze damage and root rot. However, we had decent yields of black raspberries in our field in Corbett, where O. lignaria and O. aglaia are managed. In contrast, black raspberry yield was poor at our field in Nahalem where native bees are not managed.

We do not yet know what impact the cold spring had on populations of O. aglaia and O. lignaria for the 2012 season. The bee nests have been moved from the field to our porch for protection. The nest tunnels appear to be at least half full, if not more so. Dr. Strickler plans to visit in late November to prepare the bees for winter storage and to assess this year’s bee reproduction.

Also this summer, we began working with Eric Mader of the Xerces Society out of Portland and the USDA Natural Resources Conservation Service to plant a number of alternative native flowers on the farm that will bloom before and after berry bloom, in an effort to increase native bee populations on the farm. Populations of bees such as bumble bees, which are active throughout the season, should increase when flowers are available for a longer season. The native flowers should also help support the Osmia species that have been increasing as part of this SARE-funded project.

2. Regarding our second objective, technical problems with internet connectivity for the webcam continued this season. In June, Mike Carter had time to research the cost and equipment necessary to use cell phone service to upload camera images to the web. He advised us to purchase a $560 radio data modem that would allow us to use a Verizon cell phone. Cell phone service required to upload the webcam images is estimated to cost approximately $60-65 per month and will only need to be available for the months that the bees are active.

During system maintenance in July, Mike found that the camera needed calibration and a firmware upgrade which took several hours to complete, but that is done and the camera is ready now.

The new modem was ordered and was received in mid-August, but it turned out to be the wrong model. A replacement was ordered and arrived in September. However, this was long after pollination was over. Rather than start phone service in September when we will not need the webcam, we would like to start phone service in January 2012 so that Mike has time to configure and test the system in the field and make up for any issue(s) it might encounter and that it will be ready to use by April or May when the bees are active.

• Bee shelter and solar panel for webcam (right, under power line) in black raspberry field.
• Osmia aglaia foraging on black raspberry flower

Impacts and Contributions/Outcomes

In an effort to meet our third objective, Karen has been reporting our progress on the Oregon Berry Bee Blog, http://oregonberrybee.blogspot.com/2010_06_01_archive.html.

We have also published a short article about native bees for berry pollination in the spring issue of the newsletter of the Oregon Raspberry and Blackberry Commission.

We hope by next May to have the webcam on line so other berry growers and people interested in bees and pollination can finally observe our bees in action from a distance.

The Xerces Society has suggested that we host a field day on the farm to showcase the results of the various native bee projects that are ongoing, including the SARE-funded project, the Xerces/NRCS native bee habitat project and Dr. Cane’s studies of O. aglaia.

Several other berry growers in our area have expressed an interest in our work with native bees and may be interested in trying them. Other berry growers use more pesticides than we do. However, they do not spray until after bloom is finished, so it is possible that native bee mortality could be minimized by moving the completed nests out of the field before spraying.

Peerbolt Crop Management (www.peerbolt.com ), which works with nine berry councils in the Northwest, has agreed to help us disseminate information about our native bee project in their “Small Fruit Update,” a weekly IPM email newsletter for the region’s berry industry.

We have been selling our berries at the farmers’ market and find that our customers love the idea of the bee projects on our farm. We think they would love to watch the bees from the webcam, so we may find it is a good marketing tool in addition to an educational tool for other growers.

Collaborators: