DOI: 10.5061/dryad.5x69p8d9c
title: More than mesolectic: Characterizing the nutritional niche of Osmia cornifrons

description: Characterizing the nutritional needs of wild bee species is an essential
 step to better understanding bee biology and providing suitable
 supplemental forage for at-risk species. Here, we aim to characterize
 the nutritional needs of a model solitary bee species, Osmia
 cornifrons (Radoszkowski), by using dietary protein-to-lipid ratio (P:L
 ratio) as a proxy for nutritional niche and niche breadth. We first
 identified the mean target P:L ratio (~3.02:1) and P:L collection range
 (0.75 to 6.26:1) from pollen provisions collected across a variety of
 sites and time points. We then investigated the P:L tolerance range of
 larvae by rearing bees in vitro on a variety of diets. Multifloral and
 single-source pollen diets with P:L ratios within the range of surveyed
 provisions did not always support larval development, indicating that
 other dietary components such as plant secondary compounds and
 micronutrients must also be considered in bee nutritional experiments.
 Finally, we used pollen metabarcoding to identify pollen from whole larval
 provisions to understand how much pollen bees used from plants outside of
 their host plant families to meet their nutritional needs, as well as
 pollen from individual forager bouts, to observe if bees maintained strict
 floral constancy or visited multiple plant genera per foraging bout. Whole
 larval provision surveys revealed a surprising range of host plant pollen
 use, ranging from ~5–70% of host plant pollen per provision. Samples from
 individual foraging trips contained pollen from multiple genera,
 suggesting that bees are using some form of foraging decision-making.
 Overall, these results suggest that O. cornifrons have a wide nutritional
 niche breadth, but while pollen P:L ratio tolerance is broad, a tolerable
 P:L ratio alone is not enough to create a quality diet for O. cornifrons,
 and the plant species that make up these diets must also be carefully
 considered.
description: # More than mesolectic: Characterizing the nutritional niche of *Osmia
 cornifrons*
 [https://doi.org/10.5061/dryad.5x69p8d9c](https://doi.org/10.5061/dryad.5x69p8d9c) ## Description of the data and file structure File 1 - Protein and lipid concentrations for *O. cornifrons* pollen provisions across sites and time periods in Centre Country, Pennsylvania. This data was used to create Figures 1 and 2. Rows are sample names and columns are protein concentration (ug/mg), lipid concentration (ug/mg), protein:lipid ratios, and standard deviation values for the triplicate average when calculating concentrations from machine readings. File 2 - Plant genera present in *O. cornifrons* pollen provisions, determined via pollen meta-barcoding. Rows are samples and columns are plant genera. Values are proportions of the total number of sequencing reads. This data was used to create Figures 3 and 4. File 3 - Larval survival, adult survival, number of days to cocoon completion, and number of days to adulthood/pupation of bees reared on altered multifloral pollen diets (tab 1), unaltered multifloral pollen diets (tab 2), and unaltered single-source (SS) pollen diets (tab 2). This data was used to create Figures 5, 6, 7, S1, and S2. Diet is the dietary treatment group, Plate is the well plate ID bees were on, Position is the plate well bees were in, DOY is the day of year an individual perished (only for altered multifloral pollen diets), Adult status is the adult mortality status of the individual, and Larval status is the larval mortality status of the individual. A value of 1 indicates that an individual perished before reaching that stage and 0 indicates survival. DOC is the number of days an individual took to complete a cocoon (only tab 2) and DOP is the number of days an individual took to reach adulthood (only tab 2). File 4 - Code used to run data analyses in R. ## Sequencing data access Sequences used to make data file 2 can be accessed via NCBI Sequence Read Archive under Bioproject SUB13689831. ## Code/Software Custom Python scripts were used to process meta-barcoding sequences and can be found at https://github.com/RTRichar/SimpleSequenceClassification. Code used to curate the databases used can be found at https://github.com/sbresnahan/metacleaner. Figures 1, 2, 3, 4, S1, and S2 were created in R (version 4.1.3). Code used is available in data file 5. Figures 5, 6, and 7 were created in JMP (version 16.1) and do not have available code.