Project Number: 2080-21000-017-07-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Apr 1, 2017
End Date: Mar 31, 2020
Honey bees have become increasingly unavailable and expensive for crop pollination since Colony Collapse Disorder was described and the world was alerted to CCD and many factors that negatively impact honey bee health. Although other managed pollinators, such as bumble bees, alfalfa leafcutting bees, and blue orchard bees (BOBs), are available for use on some crops, a ready BOB supply and a well-developed management system for their use are especially lacking. BOB suppliers and managers need more information to supply customers with disease- and pest-free bees, to manage bees for optimal performance for pollination, and to maintain populations in numbers large enough for profitable business and to accommodate large commercial operations. We seek to meet five objectives that tackle primary stakeholder concerns: 1) understanding variation in developmental phenology of regionally-distinct BOB populations; 2) finding the genetic basis for regional differences of BOB sources through cross-breeding/mating experiments and 3) studies of population genetics; 4) examining pest and pathogen communities of BOBs from distinct sources; and 5) describing patterns and seeking causes of BOB dispersal/loss in commercial settings.
For this 3-year proposal, field and laboratory will be employed to meet the research objectives. For Objective 1, recently-provisioned BOB nests will be collected from California (coastal and Sierras), Washington and Utah and shipped to the Pollinating Insects Research Unit (PIRU) in Logan, UT to be reared under temperature regimes that mimic the climate of their origins or constant temperatures. The length of each developmental stage and the time to emergence for each group pf bees will be measured and compared to determine the differences between natural emergence timing and emergence under managed conditions. For Objective 2, adult bees from California and Utah will be allowed to mate with each other in controlled experiments, having reciprocal and controlled crosses. To determine if there are reproductive consequences of pairing bees from regionally-distinct trapping sites, we will monitor mating behavior and reproductive output. Receptivity of males and females to mating attempts will be scored. Mated females will be allowed to nest in a greenhouse, and then the offspring will be raised at constant temperatures. Developmental time and survival will be scored, and the number of cells and sex ratio will be recorded. For Objective 3, BOBs will be trapped from various areas of the western U.S., especially from areas where BOBS are currently wild-trapped in California, Utah, Idaho, and Washington, to determine if developmental phenotypes or possibly differential mate-choice are expressed as detectable genetic population differences. Using microsatellites, the presence of historic and potential for future of genetic admixture among the western populations will be assessed in bees originating from these regional populations. How genetic differences are expressed in progeny of mixed-source populations also will be examined (as in Objective 2). For Objective 4, we will collect adult and immature samples of bees from wild-trapped and managed populations to identify all diagnosable parasites and pathogens. Arthropod pests can be diagnosed from visual inspections, x-ray examinations of nest cells, and rearing of pests from infested cells. Microbial and viral pathogens will be detected with standard molecular techniques. If the matings from BOBs from different localities are affected in ways that are not linked to genetic differences (Objective 3), the parental strains will be examined using molecular methods to determine if they differentially are infected by symbionts such as Wolbachia. For Objective 5, we will measure initial dispersal proportion and distance with respect to source population and management history. Bees raised in matched versus mismatched temperature regimes will be incubated and released in orchard settings. Bees will be marked with paint, protein markers or florescent dye for measuring dispersal from release sites and distance to chosen nest sites. Distances traveled during early, middle and post bloom periods will be examined by supplying nesting sites at varying distances in and around orchards and collecting marked bees from those sites.