1a. Objectives (from AD-416):
The overall goal of this project is to ensure the productivity and profitability of insect-pollinated crops by improving the diversity and availability of pollinators for U.S. agriculture. In general terms, we wish to create a toolbox of pollinators. To accomplish this, we seek to understand the diversity and abundance of wild bees in the U.S., and to develop methods for managing a selection of bees as pollinators, including developing effective methods for mass production, ultilization and disease control. To attain our objectives, we plan to focus on specific ecological and agricultural systems. Objective 1: Improve maintenance of wild lands and native bees by (a) enhancing knowledge of native bee pollination, systematics and biodiversity (especially for megachilidae and bombus), (b) developing identification keys that are friendly to non-experts monitoring native bees, and (c) restoring wild lands by identifying the native pollinator guilds necessary for commercial seed farming of native forbs. • Subobjective 1.1. Expand the taxonomy and systematics of native bees, especially Megachilidae, and develop user-friendly identification keys. • Subobjective 1.2. Document the diversity of native bees in the U.S. • Subobjective 1.3. Develop pollination systems for commercial production of native plant seed needed to restore plant communities on public lands in the Intermountain West. Objective 2: Deliver improved pollination management systems for non-apis bees, particularly the Alfalfa Leafcutting Bee (ALCB) and the alkali bee for alfalfa seed production, bumble bees for greenhouse and field crops, and the Blue Orchard Bee (BOB) for orchard crops. • Subobjective 2.1. Improve sustainability of commercial populations of alfalfa leafcutting bees (ALCB) used for alfalfa seed production. • Subobjective 2.2. Improve methods for maintaining alkali bees for alfalfa seed production. • Subobjective 2.3. Improve management methods of Osmia bees for crop pollination, focusing on managing blue orchard bees to pollinate almonds and Osmia aglaia for bramble fruits • Subobjective 2.4. Develop methods to increase retention of managed solitary bees, particularly the blue orchard bee and alfalfa leafcutting bee. • Subobjective 2.5. Develop management methods for bumble bees native to the U.S. Objective 3: Develop effective and grower-friendly systems for managing diseases in non-apis bees, particularly chalkbrood in the ALCB and BOB. • Subobjective 3.1. Determine chalkbrood epidemiology and diversity (through molecular systematics), and elucidate the genetics of bee immune responses and pathogen resistance. • Subobjective 3.2. Discover effective fungicides and other suppression tools,develop application methods for controlling chalkbrood in the ALCB, and use this as a model for chalkbrood control in BOB. • Subobjective 3.3. Discover the key pathogens and parasites that inhibit mass production of bumble bee colonies.
1b. Approach (from AD-416):
Bees are vital to agriculture. The commercial production of more than 90 crops are accomplished through bee pollination. The honey bee is the best known crop pollinator, but recently, honey beekeepers have been facing a bee health crises, and significant scientific time and effort has been put into identifying the cause. The issue can be viewed as a more general problem, one of a declining availability of pollinators for agriculture. As such, another approach to avoiding the crises can be taken, and that is to evaluate the diversity and use of many species of bees. Our plan addresses three main objectives (1) improve native bee diversity and abundance, and knowledge of their biology, (2) deliver improved pollinator management systems, and (3) develop effective disease management systems for non-Apis bees. Our results will develop an understanding of the causes behind pollinator declines, improve pollinator availability, improve crop quality and production for pollinated crops, and enhance the development of new cropping methods (such as covered row crops). Our overriding goal is to provide agriculture with a tool box of pollinators, however, all bees have their own diseases and parasites and are susceptible to environmental use of pesticides and loss of habitat. Research is needed to identify and control the negative impacts of these factors. In addition, many species of wild bees provide free pollination services for agricultural crops and maintain plant reproduction in our rangelands and other natural and wild areas, and thus it is important to evaluate and protect their populations.
3. Progress Report:
Pollination is vital to U.S. agriculture and maintaining our wildlands. This Project (Logan, UT) evaluated the diversity and abundance of wild bees in the U.S., and improved the management of pollination bees for agriculture. The diversity of bees is vast, but poorly described. Major needs for conserving our nation’s native bees are: 1) a stable classification system that allows users to accurately identify bees to species, 2) an understanding of the distribution and biology of different bees, and 3) digital access to this information. A phylogenetic tree of Osmia (mason bees and orchard bees), was developed using DNA from 86 species, and this tree of life will be used to understand the evolution of different bee nesting traits and the morphological adaptations that support those traits. Efforts to digitize the information associated with each specimen in The National Pollinating Insects Collection continue. The database now includes all the collection information for 1.01 million bee specimens. Bumble bee research on the development of a western species for commercial use continued, with a focus on improving methods for culturing, particularly reducing mortality in the rearing process. Assessments of the conservation status of North American bumble bees also continued. Bumble bee pathology studies were initiated to understand pathogen prevalence and control in rearing facilities. Alfalfa leafcutting bees are used extensively for alfalfa pollination, so research efforts continued with regard to improving production and disease control for this bee. Sometimes, alfalfa leafcutting bees produce two generations a year, instead of the expected one. This phenomenon was found to increase the spread of chalkbrood, a serious disease of this bee. Studies were continued to determine what causes for second generation development. Nesting females of the alkali bee, a valuable alfalfa pollinator, were found to require pollen at the end of the day for continued egg production, a fact not previously known. This means that for bees to reproduce well, flower resources must be available all day, not just in the morning. It is common for growers to apply such a large number of bees to their fields that all the nectar and pollen are used up by early afternoon, a practice that we now know reduces the ability of females to obtain the nutrients they need to continue laying eggs. Efforts to determine the sublethal effects of some fungicides and insecticides continued, including studies to determine effects on bee behavior and immune systems. Research continued to develop methods for using the blue orchard bee for pollination of orchard crops, such as almonds. Bees use chemical cues to identify good nesting locations, and the composition of these cues was identified and then used to develop a nest attractant that was then successfully field tested. Tests were also conducted to identify the optimal arrangements for deploying nesting boxes and releasing bees in orchards. Research continued with regard to native bees and their use in rehabilitating rangelands after disasters, such as wildfires and overgrazing.
1. Improved family tree for the Megachilidae (leaf-cutter, mason, carder and resin bees). Concerns about population declines have highlighted the need for a better taxonomic understanding of native bees in order to assess the status of pollinators and pollination services. ARS (Logan, UT) developed a modern, stable classification of the bee family Megachilidae that is particularly important since the numerous species in this worldwide family include most of the currently managed crop pollinators, many other potential crop pollinators, as well as many invasive bees. An analysis of living species plus all available fossil taxa resulted in a well supported tree of relationships and the identification of a new tribe of bees, Aspidosmiini. The result is a stable higher classification for Megachilidae that provides a platform for needed revisionary work on specific groups of megachilids that are important pollinators, and other groups that are potential invasives.
2. Alfalfa leafcutting bees production better in rangelands than alfalfa fields. Populations of alfalfa leafcutting bees increased on CRP rangeland in 2011, in contrast with the typical bee shortfalls experienced by U.S. alfalfa seed growers managing this bee for pollination. ARS scientists (Logan, UT) and industry collaborators obtained a 5-fold increase in the bee population, with no second generation emergence (typically a major loss factor), with only 2% egg mortality and under 1% chalkbrood (both can be 15-fold worse on grower’s farms). Remarkably, these results were obtained on a mix of tumble-mustard and sparse alfalfa, as the expected floral resources. If U.S. alfalfa seed growers could regularly use rangelands to increase a portion of their leafcutting bees, they could save substantially on the costs of buying bees from Canadian producers.
3. First field guide to western bumble bees released. Until now, there has been no field guide for identifying bumble bees of the western United States. This lack of a guide has restricted the ability of land managers and the public to identify which of the 30 western species they were encountering. To remedy this deficit, ARS (Logan, UT) partnered with the U.S. Forest Service and the Pollinator Partnership to write the 144 page “Bumble Bees of the Western United States.” The guide is helping researchers, managers, and citizens to understand the biology of bumble bees and to identify bumble bees in their area.
4. Surveys of bumble bees in Alaska, Washington, and Idaho illuminate the extent and history of recent bumble bee declines. Bumble bees are important pollinators of agricultural crops and wild lands, and their importance increases with latitude and elevation, as they have a greater cold tolerance than most other bees. ARS (Logan, UT) evaluated bumble bee natural distributions, abundances, and pathogen associations, across Alaska and the Palouse region of eastern Washington and northern Idaho. This survey documented that bumble bee species which are declining in the contiguous 48 states are healthy in AK. Furthermore, results of the Palouse survey indicate that population declines of certain species may have occurred earlier than was previously suspected. Both of these studies are published and are being used to inform further sampling by the U.S. Fish and Wildlife Service in AK, and to inform land management decisions in the agriculturally important Palouse region.
5. Commercial pollination of almonds by solitary bees proving successful. Blue orchard bees are good pollinators for tree crops such as almonds, and they can be used by releasing raised bees and providing them artificial nesting boxes. The number nest boxes deployed per acre in almond trees, but not the number of bee release points, influences the retention and nesting of blue orchard bees. ARS scientists (Logan, UT) and industry collaborators found that hanging an intermediate number of nest boxes (approx. 5-10 per acre and containing 100-200 cardboard nesting tubes) led to the production of more bees than using fewer boxes (2.5 boxes per acre), and was less labor intensive than using more boxes (20-40 boxes per acre). Bee nesting was similar when the bees were released all in one place or spread out over 15 release points. Beekeepers who supply blue orchard bees for almond pollination now have very useful information on how nest and bee deployment strategies affects bee nesting success, and nesting success is required for pollination success.
Ayala, R., Griswold, T.L. 2012. Two new species of the bee genus Peponapis, with a key to the North and Central American species (Hymenoptera: Apidae: Eucerini). Revista Mexicana de Biodiversidad. 83(2): 396-406.