DOI: 10.5061/dryad.jsxksn0hh
title: Data from: The heat is on: reduced detection of floral scents after heat waves in bumblebees

description: Global climate change disrupts key ecological processes and biotic
 interactions. The recent increase in heat wave frequency and severity
 prompts the evaluation of physiological processes that ensure the
 maintenance of vital ecosystem services such as pollination. We use
 experimental heat waves to determine how high temperatures affect the
 bumblebees’ ability to detect floral scents. Heat waves induced strong
 reductions in antennal responses to floral scents in both tested bumblebee
 species (Bombus terrestris and Bombus pascuorum). These reductions were
 generally stronger in workers than in males. Bumblebees showed no
 consistent pattern of recovery 24 hours after heat events. Our results
 suggest that the projected increased frequency and severity of heat waves
 may jeopardize bumblebee-mediated pollination services by disrupting the
 chemical communication between plants and pollinators. The reduced
 chemosensitivity can decrease the bumblebees’ abilities to locate food
 sources and lead to declines in colonies and populations.
description: The collected data are electroantennography (EAG) recordings. The
 antennal signal to stimulus was 10 times pre-amplified, converted to a
 digital signal using a DC amplifier interface (IDAC-2, Syntech) and
 recorded with GC-EAD software (GC-EAD 2014, version 1.2.5, Syntech). See
 method section of the manuscript 'Physiological experiments –
 electroantennography' for more detailed description.
 The statistical analyses were conducted in R Studio (R version
 4.3.2 (2023-10-31) -- "Eye Holes" Copyright (C) 2023 The R
 Foundation for Statistical Computing Platform. <br>The following
 packages were used: library(MASS), library(car), library(emmeans),library
 (glmmTMB), for the plots library(ggplot2) for the plots
 library(ggplot2).
description: # The heat is on: reduced detection of floral scents after heat waves in
 bumblebees
 [https://doi.org/10.5061/dryad.jsxksn0hh](https://doi.org/10.5061/dryad.jsxksn0hh) The dataset contains electroantennography (EAG) recordings of bumblebees to flower volatile stimuli. \ Experimentally, we assessed the effects of simulated heat waves on bumblebees' ability to detect flower volatiles. To this end, we compared EAG recordings of male and worker, from 2 bumblebee species, in 5 treatment conditions, to 3 flower volatiles, at 3 concentrations. 2 sets of comparisons were done: \ Comparison 1: we assessed whether workers and males detect floral scents equally by comparing EAG recordings of bumblebees from control groups (that did not undergo any experimental heat wave treatment)\ Comparison 2: we analysed the effects of simulated heat waves on antennal responses of bumblebee workers by comparing EAG recordings of bumblebees that underwent an experimental heat wave treatment (4 conditions: heat, heat + access to liquid, heat + 24h resting period before testing, heat + dry humidity conditions) and the control group. For males bumblebees we compared control group vs heat + dry humidity conditions. \ 3 concentrations of 3 flower volatiles were tested for both comparisons 1\). We found that antennal response to flower volatiles were dose-dependent (= stronger with higher concentrations), and these responses were somewhat stronger in workers than in males\ 2.) We found that experimental heat waves reduced bumblebees responses to flower volatiles for both species and both sexes in almost all instances significantly. Reductions of antennal responses were stronger in workers than in males. ## Description of the data and file structure | Meta for Data\_bumblebee\_sense\_of\_smell.csv | | | | :--------------------------------------------- | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------- | | Column | Description | | | A | unique sample identifier | | | B | Nest ID | | | C | Bumblebee species  (B. pascuorum or B. terrestris) | | | D | Sex  (male or worker bumblebee) | | | E | Treatment - 5 heat shock treatments: | | | | Cont | Control | | | HS1 | 40ºC for 2.75 h / 90% relative humidity | | | HS2\_liq | 40ºC for 2.75 h / 90% relative humidity, access to API-invert during treatment | | | HS3\_rec | 40ºC for 2.75 h / 90% relative humidity, humidity and 24 h resting time before electro antenno grams | | | HS4\_dry | 40ºC for 2.75 h / 15% relative humidity,  | | F | TreatmentNew - for plots (treatments with males got an additional 'm') | | | | Cont | Control (worker) | | | mCont | Control (males) | | | HS1 | 40ºC for 2.75 h / 90% relative humidity (worker) | | | HS2\_liq | 40ºC for 2.75 h / 90% relative humidity, access to API-invert during treatment (worker) | | | HS3\_rec | 40ºC for 2.75 h / 90% relative humidity, humidity and 24 h resting time before electro antenno grams (worker) | | | HS4\_dry | 40ºC for 2.75 h / 15% relative humidity (worker) | | | mHS4\_dry | 40ºC for 2.75 h / 15% relative humidity (males) | | G | Concentration ( concentration of floral scents: either 1ug, 10ug or 100ug) | | | H | Geraniol (electro antennal response of bumblebee to Geraniol stimulus, in mV, response variable) | | | I | Ocimen (electro antennal response of bumblebee to Ocimene stimulus, in mV, response variable) | | | J | Nonanal (electro antennal response of bumblebee to Nonanal stimulus, in mV, response variable) | | ## Sharing/Access information The data are stored at figshare for review purposes (link: [https://figshare.com/s/bcef6705c1672bf83128)](https://figshare.com/s/bcef6705c1672bf83128\)) ## Code/Software The statistical analyses were cnducted in R Studio (R version 4.2.0 (2022-04-22) -- "Vigorous Calisthenics" Copyright (C) 2022 The R Foundation for Statistical Computing Platform. The folwoing packages were used: library(MASS), library(car), library(emmeans), for the plots library(ggplot2)