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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Invasive Species and Pollinator Health » Research » Research Project #440232

Research Project: Conduct Longitudinal Studies on Colony Performance and Explore Near-term Effects of Nutritional and Agrochemical Stressors on Honey Bee Health

Location: Invasive Species and Pollinator Health

Project Number: 2030-21000-055-000-D
Project Type: In-House Appropriated

Start Date: May 13, 2021
End Date: May 12, 2026

As pollinators, honey bees (Apis mellifera) are the third most important agricultural livestock after cattle and pork, indispensable for crop production and global food security. Despite their significant economic importance, honey bees continue to face debilitating challenges from several interactive factors including poor nutrition, exposure to agrochemicals, reduced genetic diversity, devastating pests and pathogens and ongoing changes to climatic conditions. A common underlying thread is that these factors vary across seasons and across years, and their build-up leads to compounding impacts that result in patterns not easily discerned with short-term datasets. Depending on agricultural practices, some of the factors may go through cyclical trends that affect long-term performance of apiaries. To get a comprehensive understanding of factors determining honey bee health, it is necessary to obtain continuous recording of data on colony performance, survivorship, environmental factors surrounding the apiaries, agrochemical residues, and availability of nutritional forage, over long periods of time. This project will establish a Long-Term Honey Bee Research (LTHBR) system in California at the Davis ARS location, associated with the Invasive Species and Pollinator Health Research (ISPHR) unit. This LTHBR system will elucidate how key components involved in honey bee health and pollinator sustainability interact with the demand for pollination and agricultural practices. The data collected will generate insights into whether sustainable intensification of beekeeping can occur through better mitigation of stress-induced hive declines. This LTHBR system will also support the development of research projects that monitor a range of environmental conditions and correlated episodic events such as changes to nutrient flow, pest-pathogen cycles, and changing weather patterns affecting hive performance. The data collected over several years will enable the development and validation of theoretical and empirical models to forecast colony performance across various scenarios, allowing for strategies to improve pollinator health and sustainability. The following are the objectives and sub-objectives of the project plan: Objective 1: Establish longitudinal monitoring of apiaries to collect long-term data on colony performance and evaluate relative benefits of new management discoveries to improve honey bee health. Sub-objective 1A: Establish a Long-Term Honey Bee Research (LTHBR) system in California. Sub-objective 1B: Quantify the expression of hygienic behavior across the cooperator apiaries in the LTHBR system. Objective 2: Understand the effects of nutritional and agrochemical stressors on honey bee health and develop hive management strategies. Sub-objective 2A: Determine performance of honey bees under nutrient conditions relevant to California agriculture. Sub-objective 2B: Characterize how exposure to agrochemical stressors like IGRs affect honey bee reproduction, development and long-term colony stability to help beekeepers predict and mitigate the long-term consequences of agrochemical exposure.

The primary objective of this project plan is to conduct longitudinal monitoring of apiaries and collect long-term data on colony performance. As a part of Sub-objective 1A, the LTHBR system will be established in California in collaboration with commercial beekeepers, such that the different monitoring locations will be spread over the different beekeeping regions within the state. Research colonies will be established in cooperator apiaries and monitored by the Davis, California, ARS Bee lab scientists. Using a combination of laboratory and field methods, the following parameters will be recorded over the entire duration of the project plan: (1) colony performance parameters including weight, brood and food storage areas, adult bee population, queen laying patterns, honey and pollen storage areas, and prevalence of pests and pathogens including viruses, (2) reproductive performance parameters measured on queens and drones including viability of the sperm in the spermathecae of queens and in the semen of drones and (3) apiary parameters including beekeeper operating costs, their profit margins and available floral resources and their bloom time in the vicinity of the apiaries. To determine the efficacy of automated hive monitoring technologies, inhive sensors will be installed in the experimental hives. Hive performance measures recorded by the automated devices will be compared with the parameters recorded by researchers during the same time periods in the same apiaries. As a part of Sub-objective 1B, the expression of hygienic behavior, an important a form of behavioral resistance to American Foul Brood (AFB) and a behavioral defense against chalkbrood, will be quantified in the colonies of the participating stakeholder apiaries and the impact of nutrition on behavioral expression will be determined using the established Freeze Killed Brood assay. The second objective of the project plan is to determine the effects of nutritional and agrochemical stressors on honey bee health. Towards this goal, field and laboratory studies in Sub-objective 2A will determine the impact of monocrop and multi-floral pollen diets on colony-level performance measures and individual bee-level behavioral parameters. To determine the effects of agrochemical stressors on honey bee reproduction and development, laboratory studies in Sub-objective 2B will explore how Insect Growth Regulators used in almond orchards affect honey bee queen fecundity and the survival and performance of offspring.