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ARS Home » Pacific West Area » Tucson, Arizona » Carl Hayden Bee Research Center » Research » Research Project #438749

Research Project: Quantifying and Reducing Colony Losses from Nutritional, Pathogen/Parasite, and Pesticide Stress by Improving Colony Management Practices

Location: Carl Hayden Bee Research Center

Project Number: 2022-21000-022-00-D
Project Type: In-House Appropriated

Start Date: Jul 29, 2020
End Date: Jul 28, 2025

Obj. 1: Reduce bee colony losses from nutritional stress by determining the nutrients required to support optimum colony growth and queen health in the spring and summer, and in the fall to prepare bees for overwintering. Sub-obj. 1A:Determine nutrient use and storage in bees through the year. Sub-obj. 1B:Determine the seasonal balances of fatty acid nutrients required to support queen health and physiology, and worker-queen interactions linked to queen productivity and retention in the spring and summer, and in the fall prior to overwintering. Obj. 2: Determine plant growth conditions and practices that affect the nutrient composition of nectar and pollen for bees. Sub-obj. 2A:Determine whether cultivars of pollinator-dependent plants with known lipid profiles produce pollens with similar lipid profiles. Sub-obj. 2B:Determine the effects of plant growth conditions on nectar and pollen secondary metabolites. Sub-obj. 2C:Determine the effects of growth condition-dependent secondary metabolites on bees. Obj. 3: Develop methodological and statistical tools for extracting information on bee colony health and activity from continuous sensor data, apply those methods to manipulative field experiments, and relate sensor output to colony performance. Sub-obj. 3A:Correlate daily patterns of hive weight change, thermoregulation and CO2 levels with colony pest and disease status, environmental factors, gene expression and protein metrics. Obj. 4: Develop Best Management Practices for placing hives in cold storage that consider nutritional needs, parasite and pathogen spread, and optimal timing to reduce colony losses. Sub-obj. 4A:Evaluate the impact of placing bee colonies in cold storage for short periods in Sept. to Oct. with respect to colony health, survival, behavior, stress, and pest and pathogen levels. Sub-obj. 4B:Identify the optimum timing for placing colonies in cold storage to minimize winter losses and maximize populations in spring. Sub-obj. 4C:Compare survival and growth in the spring for colonies from different latitudes overwintered in cold storage. Obj. 5: Determine if improved nutrition and overwintering in cold storage reduces the impact of Varroa migration on mite population and virus levels in bee colonies. Sub-obj. 5A:Determine the relationship between mite populations and Varroa-transmitted virus levels through the year in colonies with and without supplemental pollen feeding. Sub-obj. 5B:Determine whether a Sept. miticide treatment followed by placing colonies in cold storage in Oct. affects Varroa populations, deformed-wing virus levels, and overwintering survival. Obj. 6: Quantify the impacts of exposure to agrochemicals on worker bees and queens, and the interactions of those agrochemicals with in-hive treatments against pests and diseases. Sub-obj. 6A:Measure the impact of the interaction of agricultural pesticides with in-hive pest treatments on colony growth, foraging, thermoregulation and CO2 regulation. Sub-obj. 6B:Quantify the impacts of agrochemicals and their interactions with in-hive pest treatments on queen physiology, development and replacement, and on worker-queen interactions linked to queen productivity.

Objective 1: The components of an artificial diet healthy for bees in the long term remains elusive. This project will address the roles of lipids and secondary metabolites in queen and worker bee health. Lipids are a diverse nutrient class with roles in energy production and physiological homeostasis. Essential fatty acids such as linoleic and linolenic acid, are obtained solely from pollen and needed for gland development, production of worker and royal jelly, and brood and queen rearing. How these essential lipids move through the colony and how that flux is influenced by diet will be explored. Objective 2: Pollen and nectar contain a variety of secondary metabolites such as thymol and eugenol that are produced in response to biotic and abiotic stressors. Thymol and eugenol are broad-spectrum antimicrobials that inhibit growth of bee pathogens, and both occur in flowers, including nectar. Thymol is also used as a miticide against bee pests. This project will explore how the concentrations of these secondary compounds can be manipulated via environmental conditions, and the effects of those compounds on bee diseases and colony microbiota. Objective 3: Monitoring colonies using sensors can reveal information on colony genetics, phenology, pesticide exposure and nutrition. Interest in monitoring colonies using sensors is increasing and with it the need to identify which kinds of data, such as weight, temperature and CO2 concentration, are most informative, and the most effective models and methods for extracting information from the data. Objective 4: The use of cold storage is a common method to preserve and protect colonies. This project will determine whether cold storage has the potential to induce the production of diutinus bees needed for winter survival. Cold storage may also be used to control Varroa mites by inducing colonies to reduce brood production and thus allow more effective treatment of the Varroa. The project will focus on whether the value of the improved treatment efficacy exceeds the cost of the stress on the colonies by monitoring bees on the colony and individual level. Objective 5: Varroa mites remain a major cause of bee stress worldwide; modern commercial beekeeping often involves treating colonies frequently with miticides, and placing colonies in high densities during pollination events, which puts them in contact with pests and diseases of other colonies. This project will develop recommendations to help reduce Varroa and diseases they transmit by improving colony nutrition and by exploring the application of miticides prior to cold storage to isolate colonies. Objective 6: Agrochemical exposure is considered an important stressor for honey bees, and have been shown to affect colony growth and activity, as well as queen health. In addition, beekeepers typically apply miticides against bee pests. How these different agrochemicals interact within the hive has seldom been explored. This project will focus on monitoring queen health and worker-queen interactions, as well as sensor-based measures of colony health and behavior, in controlled field studies with field-realistic concentrations of pesticides and miticides.