Synergistic negative effects between a fungicide and high temperatures on homing behaviours in honey bees
Data files
Feb 26, 2024 version files 33.91 KB
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Foraging_data.csv
11.89 KB
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Navigation_data.csv
19.24 KB
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README.md
2.78 KB
Abstract
Interactions between environmental stressors may contribute to ongoing pollinator declines, but have not been extensively studied. Here, we examined the interaction between the agricultural fungicide Pristine® (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin) and high temperatures on critical honey bee behaviours. We have previously shown that consumption of field-realistic levels of this fungicide shortens worker lifespan in the field and impairs associative learning performance in a laboratory-based assay. We hypothesized that Pristine® would also impair homing and foraging behaviours in the field, and that an interaction with hot weather would exacerbate this effect. Both field-relevant Pristine® exposure and higher air temperatures reduced the probability of successful return on their own. Together, the two factors synergistically reduced the probability of return and increased the time required for bees to return to the hive. Pristine® did not affect the masses of pollen or volumes of nectar or water brought back to the hive by foragers, and it did not affect the ratio of forager types in a colony. However, Pristine®-fed bees brought more concentrated nectar back to the hive. As both agrochemical usage and heat waves increase, additive and synergistic negative effects may pose major threats to pollinators and sustainable agriculture.
Access this dataset on Dryad: https://doi.org/10.5061/dryad.jh9w0vth8
These experiments measured the effects of the agricultural fungicide Pristine on honey bee navigation and foraging behaviours.
In the navigation experiment, bees were captured from their individual colonies (which had either been exposed to the fungicide or had served as controls), marked with either a queen tag or an RFID tag, and then released 1 km from their hive. Human observers or RFID readers recorded the time each marked individual returned to the hive.
In the foraging experiments, returning foragers from the same colonies were captured at hive entrances. Their foraging success was measured by determining the volume and sugar concentration of their crop contents and the mass of their corbicular pollen loads.
Description of data and file structure
The navigation data details whether individual bees (either exposed to the fungicide Pristine or controls) returned to their hives after being released one km away (either ‘yes’ or ‘no’, and also gives the time (in minutes) it took successful bees to return. There were three separate runs of the experiment, in October 2021, August 2022, and October 2022. Weather data were taken from the Phoenix-Mesa Gateway Airport weather station and included the air temperature (degrees Fahrenheit), cloud cover (categorical approximation), wind direction (categorical approximation), and wind speed (miles per hour).
A separate set of bees were used for the foraging experiment, although these bees came from the same colonies as in the navigation experiment. These data consist of the mass of corbicular pollen (mg), crop volume (uL), and crop sugar concentration (%) brought back to the hive by returning foragers. Each bee is classed as either a pollen, nectar, or water forager depending on the resources it carried. Run 1 (R1) occurred in August 2022, while run 2 (R2) occurred in October 2022. The temperature was the outside air temperature in degrees Fahrenheit at the time of forager collection and was taken from the same source as in the navigation experiment.
Code
The code comes in the form of two R scripts and was originally run in R version 4.2.2. The navigation code contains the models used to test the navigation data for statistical significance. We used generalized linear mixed models (lme4 package) for probability of return and mixed effects Cox models (coxme package) for time to return. Code for graphing the results (ggplot2 package) is also included.
The navigation code contains the models used to test the foraging data for statistical significance. We used linear mixed models (lme4 package).
Microsoft Excel for .csv files; R for .R files