Bee Nutritional Ecology
All animals must obtain appropriate nutrition from their environment for development, survival and reproduction. Bees specifically rely on floral rewards for nutrition: nectar provides sugars for bees' energy, while pollen provides their main source of proteins and lipids (and other micronutrients). Because larvae are dependent on pollen for development, they rely on foraging adults to provide them all their nutritional needs. But not all pollen contains the same nutritional value, differing greatly in concentrations of nutrients across species. So a foraging bee is tasked with the responsibility of finding and choosing pollen across entire landscapes that is appropriate for their offspring, perhaps finding a single pollen perfectly suited for them, or more likely balancing their nutrition across multiple species. Foraging behavior itself can be considered to be completely adapted by animals to sense, assess, choose, consume, and respond to food sources based on their nutritional needs.
Through our research, we found that bumble bee foraging preferences for host-plant species are dependent on pollen nutritional value, specifically high protein:lipid ratios (P:L), approximately 5:1 P:L and as pollen depleted from flowers, they would then go to the next highest P:L pollen species (2nd figure left). They showed the same preferences when we gave them choices between pollens without any other floral cues, and even showed the same preferences when we modified the P:L values (Vaudo et al. 2016 PNAS). We found with synthetic diets, bumble bees survived best on and could regulate their diet to these high P:L values (Vaudo et al. 2016 JEB). And in an open ecosystem, entire colonies of bumble bees brought home on average 4:1 P:L pollen across the season (Vaudo et al. 2018 Ecol Evol; 3rd figure left). This research revealed that foragers can sense and regulate their nutritional intake from multiple pollen sources to a particular P:L ratio that is best for their own health. And perhaps some specialized flowers (such as Senna, top figure left), by providing a specific bee species particular nutritional needs, may have coevolved to match bees particular behaviors and morphological traits. But what about other bee species other than bumble bees? We believe that different bee species have their own species-specific nutritional needs, likely different than bumble bees, and this may result in different host-plant preferences. When all bees and flowers and taken into account we can see how different bee species overlap on different plant species as they all are balancing their diet to their own needs. This creates a community of interactions of bees and flowers that are all linked together in a complex network. We are currently exploring how nutrition works at the community level by characterizing nutritional landscapes provided by plants and nutritional niches of bee species. We recently published a study and dataset of over 80 plant species and 3 bee species P:L ratios and discuss discuss how these data reveal broad patterns of floral reward system, phenotype, and bee foraging strategies (Vaudo et al. Insects 2020, fourth figure left). Understanding that when a diverse group of bees and flowers work together as a community, this creates a stable ecosystem where all flowers are receiving efficient pollination by particular bee species and all bees are given the opportunity to select and choose their own appropriate nutrition. By considering bee nutrition, we can extend this concept to address important topics such as sustainable and efficient crop pollination and habitat restoration and conservation (Vaudo et al. 2020, fourth figure left; Vaudo et al. 2015 COIS, bottom figure left) |
Associated Labs: Grozinger Lab Tooker Lab Leonard Lab
Published Manuscripts
Published Manuscripts
- Vaudo AD, Tooker JF, Patch HM, Biddinger DJ, Coccia M, Crone MK, Fiely M, Francis JS, Hines HM, Hodges M, Jackson SW, Michez D, Mu JP, Russo L, Safari M, Treanore ED, Vanderplank M, Yip E, Leonard AS, Grozinger CM. (2020) Pollen protein:lipid macronutrient rations may guide broad patterns of bee species floral preferences. Insects. 11:130 pdf
- Russo L, Keller J, Vaudo AD, Grozinger CM, Shea K. (2020) Warming increases pollen lipid concentration in an invasive thistle, with minor effects on the associated floral-visitor community. Insects. 11:20 pdf
- Treanore ED, Vaudo AD, Grozinger CM, Fleischer SJ. (2019) Examining the nutritional value and effects of different floral resources in pumpkin agroecosystems on Bombus impatiens worker physiology. Apidologie. doi: 10.1007/s13592-019-00668-x pdf
- Russo L, Vaudo AD, Fisher J, Grozinger CM, Shea K. (2019) Bee community preference for an invasive thistle associated with higher pollen protein content. Oecologia. doi: 10.1007/s00442-019-04462-5 pdf
- Vaudo AD, Farrell LM, Patch HM, Grozinger CM, and Tooker JF. (2018) Consistent pollen nutritional intake drives bumble bee (Bombus impatiens) colony growth and reproduction across different landscapes. Ecology and Evolution. 8: 5765-5776 pdf
- Vaudo AD, Stabler D, Patch HM, Tooker JF, Grozinger CM, and Wright G (2016) Bumble bees regulate their intake of essential protein and lipid pollen macronutrients. Journal of Experimental Biology. 219: 3962-3970 pdf
- Vaudo AD, Patch HM, Mortensen DA, Tooker JF, and Grozinger CM (2016) Macronutrient ratios in pollen shape bumble bee (Bombus impatiens) foraging strategies and floral preferences. Proceedings of the National Academy of Sciences. doi: 10.1073/pnas.1606101113 pdf
- Vaudo AD, Tooker JF, Grozinger CM, Patch HM (2015) Bee nutrition and floral resource restoration. Current Opinion in Insect Science. 10: 133-141. (most cited article in journal as of June 26, 2017) pdf
- Vaudo AD, Patch HM, Mortensen DA, Grozinger CM, and Tooker JF (2014) Bumble bees exhibit daily behavioral patterns in pollen foraging. Arthropod-Plant Interactions. 8: 273- 283 pdf
Phylogeny vs Function:
predicting interactions across biomes
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Observing community level interactions of bees and flowers can be very confusing, it may appear at times that there is no way to predict what bees visit what flowers. When we think that a specific bee and flower have a one-to-one relationship, if we look long enough, we often find that it's not true. In general, bee-flower communities are generalized. Yet we don't see all bees on all flowers either. And as we go to different environments, sometimes the relationships we observed before are not the same anymore. So how do we know what bee-flower relationships we should expect to observe, and how do we know when these relationships are changing?
Above we argue that bees choose flowers based on the fundamental need for nutrition, and there are other aspects that are important too, such as physical access to those resources. A bee must be able to insert its tongue or body into the flower and manipulate the flower to receive pollen or nectar rewards. So there may be a size based relationship between bees and flowers for efficient access to floral rewards and efficient pollination services. And these sizes may be conserved within each bee and flower genus or tribe or even family, yet still converge on particular size niches across phylogenetic distance. The ultimate question is, do naive bees when they first emerge go and find resources that are most easily accessible to them, or do they have innate preferences for particular plant families or genera? One way of looking at this is observing interactions across different types of neighboring environments to see if the bee-flower relationships remain consistent or change. In South Africa, there are many different distinct plant biomes that share related plant and bee species. I spent over a year observing and measure bee-flower interactions across these biomes to create a dataset to address the question of how phylogeny and function operate to unify pollination networks across space and time. These observations can reveal how plants and pollinators occupy, differentiate, and coevolve in novel environments across evolutionary time. |
Associated Lab: The Johnson Pollination Research Lab
Stay tuned for publications by Vaudo AD and Johnson SD
Stay tuned for publications by Vaudo AD and Johnson SD
Utilizing Genetic Information from Collections
Excited to announce that this project was selected for Insect Systematics and Diversity special collection Teaching Resources
Tens of thousands of insects are deposited in collections every year as a result of survey-based studies that aim to investigate ecological questions. Yet these collections are seldom used outside of classification of the insect specimens. We can reopen the utility of these collections by using DNA-based techniques to explore the bees' demographic and evolutionary history, temporal changes in their abundance, and pathogen dynamics. Using museum collections of the non-model squash bee species (Eucera (Peponapis) pruinosa), we developed a standard minimally-destructive and budget-friendly protocol to extract DNA and amplify common gene-fragments for barcoding, phylogenetic analysis, and pathogens. We also generated genome-wide single nucleotide polymorphism (SNP) data from DNA sequencing (ddRADseq) libraries for analysis of population structure. We systematically studied the effect of specimen age (≤10 years ago) and tissue type (whole bees vs. abdomen) on DNA quality, single gene-fragment amplification, and ability to generate reliable pop-gen data. We found that all analyses were achievable with both tissue types, yet with variable levels of efficiency because of general DNA degradation. Specifically, we found that not all samples yielded satisfactory results for molecular studies; however, we did not find a systematic effect of specimen age on DNA quality which is encouraging for future studies involving historical specimens. We report the first evidence for the presence of the microsporidian pathogen Nosema spp. in squash bees, opening a window for the study of historical changes in disease pressure in this important agricultural pollinator. Our protocols can be used as a template for the design of future experiments that extract multiple pieces of information using DNA-based methods from insect museum stored specimens. |
Associated lab: López-Uribe Lab
Published manuscripts:
Vaudo AD, Fritz ML, and López-Uribe MM. (2018) Opening the door to the past: Accessing phylogenetic, pathogen, and population data from museum curated bees. Insect Systematics and Diversity. doi: 10.1093/isd/ixy014 pdf
Published manuscripts:
Vaudo AD, Fritz ML, and López-Uribe MM. (2018) Opening the door to the past: Accessing phylogenetic, pathogen, and population data from museum curated bees. Insect Systematics and Diversity. doi: 10.1093/isd/ixy014 pdf
The Pollen of Bee Nests
What if we could look into the nests of different bee species? Most bees are solitary; the foraging female creates individual cells in their nests which they lay an egg on a big ball of pollen they collected. Their offspring will then eat this pollen as it develops into an adult. As mentioned earlier, pollen is the bees main source of nutrition. So what pollen is actually in the nest's cells would be what bees are actively collecting and feeding their offspring over multiple foraging bouts. So looking at the pollen species composition and nutritional value in the actual cells would reveal to us the truth about how bees are utilizing their pollen landscape to achieve specific nutritional values.
Analyzing and identifying pollen species composition of loads is difficult to do through morphology alone. New genetic techniques are available to us to determine the composition of multi-species mixes of pollen, called metabarcoding. We are currently exploring this technique to determine what pollen species are preferred by Osmia cornifrons (Japanese Orchard Bee). This bee was introduced from East Asia in the 1970s and is a managed pollinator for orchard crops such as apple, cherry, and peach. Our study will reveal the bees' phylogenetic pollen affinities that helped it establish in the United States and we discuss how we can infer its pollination effectiveness. We currently have plans to expand this analytical technique to other wild and managed bee species. |
Associated Labs: López-Uribe Lab Leonard Lab
Published Manuscripts
Vaudo AD, Biddinger DJ, Sickel W, Keller A, and López-Uribe MM. Introduced bees (Osmia cornifrons) collect pollen from both coevolved and novel host-plant species within their family-level phylogenetic preferences. Royal Society Open Science. 7: 200225. doi: http://dx.doi.org/10.1098/rsos.200225
Published Manuscripts
Vaudo AD, Biddinger DJ, Sickel W, Keller A, and López-Uribe MM. Introduced bees (Osmia cornifrons) collect pollen from both coevolved and novel host-plant species within their family-level phylogenetic preferences. Royal Society Open Science. 7: 200225. doi: http://dx.doi.org/10.1098/rsos.200225
Interactions of Native and Introduced Bees
As managed bees have been transported throughout the world, there has been increasing concern about effects on native ecosystems and interactions with native pollinators. This is because managed bees, especially honey bees and bumble bees, although effective crop pollinators, come in bulk. They are social and form large colonies, so their introduction into novel landscapes in high quantities may occupy and remove a significant amount of the floral resources available needed by native bees. Furthermore, managed pollinators tend to have associated parasites, viruses, and other potential harmful bests that can be passed on to other pollinators on flowers. Therefore, we seek projects and collaborations with researchers and growers to help us address these concerns and determine the extent that managed and introduced pollinators effect or become naturalized into novel ecosystems.
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Associated Lab: López-Uribe Lab
Honey Bee Nest Site Selection
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Nest site selection is a crucial process in the lives of many animal species. In the security of the nest, animals seek shelter from weather and predators, store food for their future needs, and raise often immobile offspring in a safe environment. Honey bee nest site searching and decision making behavior has been well studied in classic research by Tom Seeley in the USA. In our research project, we went to honey bees' native habitat in South Africa to determine their nest-site preferences and how nest-site differences correlate to the strength of colonies.
I tracked down wild honey bee colonies on farms and reserves using a beelining technique where you attract honey bees to a food source and follow them back to their nest. Once at the nest, I extracted comb and the bees to measure various aspects of the colonies such as total population, cavity volume, and amount of honey, pollen, and brood. Well protected nesting sites in trees and cliffs are limited in South Africa, likely forcing many colonies to nest underground in old holes left by termites or burrowing mammals. Likely because underground nests are more likely to be attacked by honey hungry animals, the bees did not store as much honey and were smaller colonies, perhaps because they have to be ready to leave at any given moment. On the other hand, colonies in cliffs and trees had higher levels of honey and pollen storage and comb appeared much older. Protected nest sites are in high demand and colonies that can gain access, occupy and defend these cliff and tree nests are going to be quite successful. |
Associated Lab: Honey Bee Research and Extension Lab
Published Manuscripts
Published Manuscripts
- Human H, Brodschneider R, Dietemann V, Dively G, Ellis JD, Forsgren E, Fries I, Hatjina F, Hu F, Jaffé R, Jensen AB, Köhler A, Magyar JP, Özkýrým A, Pirk CWW, Rose R, Strauss U, Tanner G, Tarpy DR, van der Steen JJM, Vaudo A, Vejsnæs F, Wilde J, Williams GR, and Zheng H (2013) Miscellaneous standard methods for Apis melliferaresearch. Journal of Apicultural Research. 52(4): doi: 10.3896/IBRA.1.52.4.10 pdf
- Vaudo AD, Ellis JD, Cambray GA, and Hill M (2012) Honey bee (Apis mellifera capensis/A. m. scutellata hybrid) nesting behavior in the Eastern Cape, South Africa.Insectes Sociaux. 59: 323-331. pdf
- Vaudo AD, Ellis JD, Cambray GA, and Hill M (2012) The effects of land use on honey bee (Apis mellifera) population density and colony strength parameters in the Eastern Cape, South Africa. Journal of Insect Conservation. 16: 601-611. pdf