About

David R. Tarpy is a Professor and Extension Apiculturist at North Carolina State University within the College of Agriculture and Life Sciences, Department of Applied Ecology. He holds a BS in Biology from Hobart College, an MS in Biology from Bucknell University, and a Ph.D. in Entomology from the University of California, Davis. His research focuses on the behavioral ecology of insect societies, particularly honey bee queen behavior, with an emphasis on understanding the proximate and ultimate mechanisms that influence colony health and productivity. His lab investigates several key areas including polyandry and intracolony genetic biodiversity, molecular and pollinator ecology, oxidative stress and social immunity, integrated pest management of parasites and pathogens, and the reproductive quality of queens. His work aims to address both basic scientific questions and practical challenges faced by beekeepers, especially in the context of declining honey bee populations. In addition to his research, Dr. Tarpy leads extension programs that disseminate information about honey bee management to the public and beekeeping groups, working with various associations and initiatives such as the online Beekeeper Education & Engagement System (BEES) and the NC State Queen & Disease Clinic.

Research topics

• Biology
• Toxicology
• Botany
• Ecology
• Zoology
• Genetics
• Animal science
• Food science

Selected publications

• Impact of Two Common Beekeeper-Applied Chemicals on Honey Bee Queen Fecundity and Gut Microbial Communities

  Microbial Ecology · 2026-04-10

  articleOpen accessSenior author

  Like many agricultural animal systems, common apiculture (honey bees) practice has led to a reliance on chemical treatments to mitigate parasites and diseases. These agrichemicals typically take the form of acaracides (e.g., amitraz) and antibiotics (e.g., oxytetracycline; OTC), both of which can persist in various hive matrices and have unforeseen effects on colony health, such as the evolution of resistance by disease agents or decreased reproductive fertility of the bees themselves. The honey bee microbiome is a critical component of the food-processing and pathogen response of honey bees and has been shown to be impacted by agrichemicals, although the bulk of the research has been on honey bee workers, rather than the queen, which is commonly the sole reproductive of the colony, possesses her own distinct microbiome, and is strongly buffered from the external environment by alloparental care from the workers. Over the course of three experiments, we exposed queens to amitraz, OTC, or control in an industry-standard apiary. Queens were assessed for morphological, reproductive, and microbiome traits, and male and female brood were assessed for survival to pupation. We found that amitraz negatively impacts the viability of stored sperm in queens (from 87.3 ± 8.9% to 65.4 ± 7.5%) but not egg laying or brood survival. OTC disrupts the microbiome community in queens, altering community composition, but not alpha diversity. In these studies, microbial and reproductive phenotypes appear to be unrelated, suggesting a more nuanced relationship between the honey bee queen microbiome and overall colony social organization.

  PublisherDOI

• Foraging behaviors of bees (Hymenoptera Apoidea) within complex pollinator habitats

  Ethology Ecology & Evolution · 2026-03-30

  article
  PublisherDOI

• Morphometric photographs of queen honey bees originating from Canada, the U.S., Australia, Chile, and Italy

  Open MIND · 2026-01-08

  dataset

  Honey bee queens were sampled from diverse global origins to investigate relationships between morphometrics and pheromone profiles. Queens were sourced from producers in Italy, Australia, Chile, and multiple sources within the U.S. and Canada. We acquired high resolution images of n=95 queen heads, wings, basitarsi, ovaries, and spermathecae, which can be further analyzed to extract morphometric information using image processing software.

  DOI

• Morphometric photographs of queen honey bees originating from Canada, the U.S., Australia, Chile, and Italy

  Open Collections · 2026-01-01

  datasetOpen access

  <b>Abstract</b><br/><p>Honey bee queens were sampled from diverse global origins to investigate relationships between morphometrics and pheromone profiles. Queens were sourced from producers in Italy, Australia, Chile, and multiple sources within the U.S. and Canada. We acquired high resolution images of n=95 queen heads, wings, basitarsi, ovaries, and spermathecae, which can be further analyzed to extract morphometric information using image processing software. </p>

  PublisherDOI

• Foraging behaviors of bees (Hymenoptera Apoidea) within complex pollinator habitats

  Figshare · 2026-03-30

  articleOpen access

  Foraging dynamics and energetics play critical roles in pollination efficiency and plant fitness. Bees are among the most efficient pollinators; therefore, understanding their foraging patterns can elucidate their ecosystem services. We examined two aspects of foraging behavior: floral fidelity (a pollinator’s consistency in visiting the same plant species) and handling time (the time an individual spends on a single bloom). Unlike previous studies that primarily focus on an individual bee species or simplified habitats, we investigated the foraging behaviors of bee communities within complex pollinator habitats. Study sites included eight research stations across North Carolina. In Experiment 1, we analyzed the pollen grains from five focal bee species caught on 18 different plant taxa to quantify the floral fidelity of individual bees. In Experiment 2, we filmed naturally foraging bees across nine bee and plant taxa to calculate their handling and interflower durations. Comparison of floral fidelity for previously studied bee species was consistent with the literature, but we found substantial variability within and among taxa. Handling time did not vary significantly by pollinator genus, but bee traits (such as body size and tongue length) as well as flower genera, shape, and size played a role. While interflower time likewise did not differ by bee genus, smaller bees were found to have lower interflower time. Our findings suggest that individuals may be visiting more flowers of different species than previously thought, or that blooms may harbor cross-contamination of pollen grains. These results can be used to evaluate habitat effectiveness and inform conservation efforts. ● Studied foraging behavior. ● Floral fidelity varied among bee and plant taxa. ● Bee and floral traits played a significant role in floral handling time.

  PublisherDOI

• Foraging behaviors of bees (Hymenoptera Apoidea) within complex pollinator habitats

  Figshare · 2026-03-30

  articleOpen access

  Foraging dynamics and energetics play critical roles in pollination efficiency and plant fitness. Bees are among the most efficient pollinators; therefore, understanding their foraging patterns can elucidate their ecosystem services. We examined two aspects of foraging behavior: floral fidelity (a pollinator’s consistency in visiting the same plant species) and handling time (the time an individual spends on a single bloom). Unlike previous studies that primarily focus on an individual bee species or simplified habitats, we investigated the foraging behaviors of bee communities within complex pollinator habitats. Study sites included eight research stations across North Carolina. In Experiment 1, we analyzed the pollen grains from five focal bee species caught on 18 different plant taxa to quantify the floral fidelity of individual bees. In Experiment 2, we filmed naturally foraging bees across nine bee and plant taxa to calculate their handling and interflower durations. Comparison of floral fidelity for previously studied bee species was consistent with the literature, but we found substantial variability within and among taxa. Handling time did not vary significantly by pollinator genus, but bee traits (such as body size and tongue length) as well as flower genera, shape, and size played a role. While interflower time likewise did not differ by bee genus, smaller bees were found to have lower interflower time. Our findings suggest that individuals may be visiting more flowers of different species than previously thought, or that blooms may harbor cross-contamination of pollen grains. These results can be used to evaluate habitat effectiveness and inform conservation efforts. ● Studied foraging behavior. ● Floral fidelity varied among bee and plant taxa. ● Bee and floral traits played a significant role in floral handling time.

  PublisherDOI

• Morphometric photographs of queen honey bees originating from Canada, the U.S., Australia, Chile, and Italy

  Open MIND · 2026-02-02

  datasetOpen access

  <b>Abstract</b><br/><p>Honey bee queens were sampled from diverse global origins to investigate relationships between morphometrics and pheromone profiles. Queens were sourced from producers in Italy, Australia, Chile, and multiple sources within the U.S. and Canada. We acquired high resolution images of n=95 queen heads, wings, basitarsi, ovaries, and spermathecae, which can be further analyzed to extract morphometric information using image processing software. </p>

  OA PDFDOI

• Virus infection of honey bee queens alters lipid profiles and indirectly suppresses a retinue pheromone component via reducing ovary mass

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-26 · 1 citations

  preprintOpen access

  Summary Virus infections reduce honey bee ( Apis mellifera ) ovary mass (in part due to resource-allocation trade-offs with immunity) and are linked to the presence of supersedure cells in colonies, indicating that workers are attempting to replace their queen. Pheromones, lipids, and lipid transport proteins could mediate relationships among virus infection, ovary mass, and supersedure. When we infected honey bee queens in the laboratory and profiled their queen retinue pheromone (QRP) components from head extracts, we found that virus infections specifically reduced the QRP component methyl oleate. Data from an observational field study were consistent with this pattern. Lipidomics analysis of the same extracts suggests that virus infection decreases triacylglycerol abundances (major sources of stored energy). Reducing ovary mass via laying restriction was sufficient to lower methyl oleate abundance ― suggesting that virus infection reduces methyl oleate indirectly via ovary effects ― but was insufficient to reduce abundance of most triacylglycerols or stimulate immune effector expression. Abundance of circulating apolipophorin-III, a lipid transporter and putative potentiator of immune effectors, was lower in queens with restricted laying, suggesting that its expression may be controlled by nutrient availability while its immune-stimulating capacity is governed by other mechanisms. Prior research has shown that queen pheromone blends lacking methyl oleate are less attractive to workers; therefore, diminishing methyl oleate could result in a less desirable pheromone bouquet and possibly stimulate supersedure. The mechanism of methyl oleate reduction is yet to be determined, but is clearly tied to ovary size and possibly resource availability or mobilization.

  PublisherOA PDFDOI

• Pheromone and morphometric features of honey bee (Apis mellifera) queens from around the globe

  Research Square · 2025-09-25

  preprintOpen access
  PublisherOA PDFDOI

• Western red cedar (Thuja plicata) beehives have no impact on honey bee (Apis mellifera) overwintering colony survival or detoxification enzyme expression

  PLoS ONE · 2025-04-09 · 1 citations

  articleOpen access

  In North America, wooden honey bee hives are most often constructed from pine, but some companies also produce and sell boxes made of western red cedar (Thuja plicata) as a result of its local availability and desirable properties. However, there is debate within the beekeeping community about whether cedar is a safe hive material for bees, since resins within the wood are known to be insecticidal or insect deterrents. There is very little empirical evidence to support or refute these arguments. Here, we recorded health metrics of honey bee nucleus colonies hived in western red cedar and pine boxes (n = 10 each) to determine if the type of wood affects colony outcomes. Colonies were produced and introduced into these boxes in late July, with monitoring continued until the following spring. We found no significant differences in adult bee populations, brood areas, or Varroa mite prevalence among colonies hived in cedar versus pine boxes at either the end of summer (September 1st) or spring (April 1st) assessments. Overwintering survival was identical in the two groups at 90%. Hemolymph detoxification enzyme expression differed strongly between callow (day-old) workers and foragers but did not differ with hive material. Overall, we did not find evidence that hiving honey bee colonies in boxes constructed of western red cedar had any negative or positive effect on bee physiology or colony outcomes.

  PublisherDOI

Frequent coauthors

• Alison McAfee

  University of British Columbia

  53 shared

• Leonard J. Foster

  University of British Columbia

  48 shared

• Esmaeil Amiri

  28 shared

• Abigail Chapman

  University of British Columbia

  28 shared

• Micheline K. Strand

  26 shared

• Jeffery S. Pettis

  Salisbury University

  26 shared

• Olav Rueppell

  University of Alberta

  25 shared

• Bradley N. Metz

  North Carolina State University

  18 shared

Labs

• Applied EcologyPI

Education

• Ph.D., Ecology

  North Carolina State University

  1994

• M.S., Ecology

  North Carolina State University

  1991

• B.S., Zoology

  University of North Carolina at Chapel Hill

  1988