DOI: 10.5061/dryad.n02v6wx7z
title: Data: Impact of thermal stress during pupal development in a key pollinator

description: The increasing frequency and intensity of extreme thermal events like
 heatwaves, driven by climate change, threaten global biodiversity and
 entire ecosystems. Despite alarming projections of population declines for
 key pollinators like bumblebees, little is known about the direct impact
 of varying elevated temperatures during their pupal development. To gain a
 better understanding of the dose-response to thermal stress, we
 experimentally exposed Bombus terrestris L. (Hymenoptera: Apidae) pupae in
 vitro to varying thermal stress lengths (3-7 days) and intensities
 (36-38°C). This mechanistic approach allowed us to uniquely isolate the
 direct physiological effects of temperature on pupal development from
 complex colony dynamics and assess individual emergence success,
 developmental duration, body size, relative lipid content, and wing
 geometric morphometrics. At the critical threshold of 38°C, pupal
 emergence was drastically reduced (2-5 fold) and wing deformities
 increased (4-7 fold). Even excluding wing deformities, we found thermal
 stress-induced effects on emerged worker wing shape and directional
 asymmetry. Hence, our findings suggest that increased extreme thermal
 stress negatively impacts bumblebee pupal development. Given the relative
 heat tolerance of B. terrestris, we expect even greater vulnerability in
 more cold-adapted bumblebee species.
description: # Impact of thermal stress during pupal development in a key pollinator
 Dataset DOI: [10.5061/dryad.n02v6wx7z](10.5061/dryad.n02v6wx7z) ##
 Description of the data and file structure This README provides
 information about the data files associated with the manuscript titled
 "Impact of thermal stress during pupal development in a key
 pollinator". These data files contain the datasets and RMD script on
 which our statistical analysis is based.  ### Files and variables ####
 Data File: Data_ThermalStress_pupae.csv This is the main data file,
 containing: id = Bee ID\ colony =Colony name/ID\ collected = Date when 4th
 instar larva was collected\ treatment = Treatment group to which a larva
 was assigned\ temp = Temperature (in °C) the larva was exposed to\ dur =
 Duration (in days) for which the larva of exposed\ date_start = Date when
 larva pupated, and the treatment started\ date_hatching = Date when larva
 emerged as an adult\ date_death = Date when individual died\ emerged =
 Classifier if an adult bee emerged (1 = emerged; 0 = died before)\
 days_to_emergence = Duration (in days) required for the pupa to develop
 into adults\ sex = Identified sex in adult bees (male or female)\
 wing_develop = Wing development (developed = “normally” developed;
 deformed = noticeable wing deformities)\ itd = Intertegular distance (in
 mm)\ head_width = Head width (in mm)\ mass_pupae = Pupae mass at the start
 of the experiment (in mg)\ mass_adults = Adult mass after emergence (in
 mg)\ dry_mass = Adult dry mass (in mg)\ lipid_mass = Adult lipid mass (in
 mg)\ rel_lipid_content = Relative lipid content = lipid_mass/dry_mass ####
 Data File: tpsData.txt This data file contains the tps coordinates for
 wing geometric morphometric analysis.\ LM=20 = indicates 20 landmarks,
 which are provided in the following 20 lines as x-y-coordinates\ IMAGE =
 image file name\ ID = sample ID\ SCALE = scale of 1 mm in the image ####
 Data File: Laußer_Kurze_tableS1_cohorts_ESM.csv This is a data summary
 table S1, showing the exact sample size (n) per sampling cohort. colony
 =Colony name/ID\ treatment = Treatment group to which a larva was
 assigned\ collected = Date when 4th instar larva was collected\ n = sample
 size of pupae assigned to respective treatment group per cohort ##
 Code/software #### Script Files: Laußer_Kurze_2025_RMD_CodeAndOutput.pdf
 This is the R Markdown PDF output containing the complete R code for
 reproducing the statistical analysis and figures presented in our
 manuscript. #### Script Files: Laußer_Kurze_2025_RMD_ESM.Rmd This is the R
 Markdown file containing the entire R code for reproducing the statistical
 analysis and figures presented in our manuscript.