Microsporidian parasite impairs colony fitness in bumblebees
Data files
Feb 21, 2025 version files 70.15 KB
Abstract
Emerging infectious diseases can have a major impact on the fitness of novel hosts, thereby contributing to ongoing species declines. In social insects, collaborative brood care by workers and successful mating of male sexuals are key to colony fitness. The microsporidian endoparasite, Nosema ceranae, has spread almost globally, shifting across honeybee species and now to bumblebees. However, despite N. ceranae being linked to recent population declines, its possible impact on bumblebee colony fitness remains poorly understood. Here, we show that N. ceranae infections can significantly impact Bombus terrestris worker feeding glands, as well as the longevity, sperm quality, and mating abilities of drones. In the laboratory, workers and drones were exposed to either the parasite or not. Then, parasite infection rates and loads, as well as lethal and sublethal parameters were assessed. Infected drones revealed higher parasite infection rates and spore titres as well as mortality compared to female workers, suggesting sex-specific susceptibility. Furthermore, infections impaired feeding glands, sperm traits, and altered mating behaviour - all of which are key to colony fitness. Our findings provide a mechanistic explanation on how N. ceranae contributes to the ongoing decline of wild bumblebee populations, calling for respective mitigation measures.
GENERAL INFORMATION
- Title of Dataset: Microsporidian parasite impairs colony fitness in bumblebees
- Author Information
A. Principal Investigator Contact Information
Name: Domenic W. Camenzind
Institution: Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
Address: Schwarzenburgstrasse 161, 3097 Liebefeld, Bern, Switzerland
Email: domenic.camenzind@unibe.ch - Date of data collection (single date, range, approximate date): Between May and September 2019
- Geographic location of data collection: The study was performed at the Institute of Bee Health (IBH), University of Bern, Switzerland
- Information about funding sources that supported the collection of the data: Support was provided by the Vinetum Foundation to L.S. There was no additional external funding received for this study.
DATA & FILE OVERVIEW
- File List: Excel file (Microsporidian parasite impairs fitness in bumblebees_Dryad.xlsx) has three sheets. Sheets 1 (Consumption_Survival), 2 (Mating), and 3 (HPG) have the complete raw data required to repeat all the statistical analyses.
- Relationship between files, if important: Yes, however, all statistical tests can be run independently as all the relevant data is provided per sheet.
- Additional related data collected that was not included in the current data package: None.
- Are there multiple versions of the dataset? No.
DATA-SPECIFIC INFORMATION FOR SHEET 1 ('Consumption_Survival'):
- Number of variables: 17
- Number of cases/rows: 248
- Variable List:
Specimen: Number identifying each individual bees
Treatment: This is the name of the respective treatment
Sex: Sex of the bee: male (1) or female (2)
Start_mass_[mg]: Mass in mg of the individual at the begin of the experiment
End_mass_[mg]: Mass in mg of the individuals surviving of the experimental period
Mass_change_[mg]: Start mass [mg] - End mass [mg]
Survival: Days the bee survived during the experimental perion
Status: Did the bee survive the entire experimental period, yes (1) or no (0)
Consumption_SW_1: Amount of sugar water consumed during experimental days 0-4
Consumption_SW_2: Amount of sugar water consumed during experimental days 4-8
Consumption_SW_3: Amount of sugar water consumed during experimental days 8-12
Total_SW: Total sugar water consumed, sum of Consumption SW 1, Consumption SW 2 and Consumption SW 3
Total_Pollen: Amount of pollen the bee consumed [g]
Spore_count: Total spores found in gut of surviving individuals
Sperm_count: Total sperm count of surviving drones
Sperm_viability_[%]: Viability of sperm in % of surviving drones
Total_living_sperm: Sperm_viability [%] * Sperm_count
- Missing data codes: NA.
- Specialized formats or other abbreviations used: None.
DATA-SPECIFIC INFORMATION FOR SHEET 2 ('Mating'):
- Number of variables: 9
- Number of cases/rows: 45
- Variable List:
Gyne_ID: Number of the individual gyne (i.e., specimen)
Drone_ID: Number of the individual drone mated with the gyne (i.e., specimen), corresponds to "Specimen" in the "Consumption & Survival" sheet
N_Nosema_spores: Number of spores found in the gut of the drone
Treatment: Control (1) or parasite (3) treatment
Round: Mating round of drone, if not successful drones were submitted to a second round.
Start: Time of the day when drone & gyne were placed into mating arena together in HH:MM
Copulation_Start: Time of the day when copulation started in HH:MM
Copulation_End: Time of the day when copulation finished in HH:MM
Recognition_duration: Time passed between placing drone & gyne in mating arena and begin of copulation in HH:MM (i.e. "Start" - "Copulation Start")
Mating_duration: Time passed between start and end of copulation in HH:MM
Successful_mating: Did the drone manage to initiate mating with the gyne? Yes (1) or no (0)
Sperm_viability: Viability of sperm in % of drone
Sperm_count: Total sperm count of drone
Total_living_sperm: Sperm_viability * Sperm_count
- Missing data codes: NA.
- Specialized formats or other abbreviations used: None.
DATA-SPECIFIC INFORMATION FOR SHEET 3 ('HPG'):
- Number of variables: 4
- Number of cases/rows: 885
- Variable List:
Bee_ID: Number of the individual worker bee, corresponds to "Specimen" in the "Consumption & Survival" sheet
Treatment: Treatment group
Measurement: Number of measurement conducted per bee, in total 30 repetitions
HPG_Diameter_[µm]: Diameter of individual HPG-acini in µm
- Missing data codes: NA.
- Specialized formats or other abbreviations used: None.