DOI: 10.5061/dryad.0k6djhb7s
title: Data from: Stingless bee foragers experience more thermally stressful microclimates and have wider thermal tolerance breadths than other worker subcastes

description: The current state of anthropogenic climate change is particularly
 concerning for tropical insects, species predicted to be the most
 negatively affected. Researching climatic tolerance in social insects is
 challenging because adaptations exist at both individual and societal
 levels. Division of labor research helps to bridge the gap between our
 understanding of these adaptations at different scales, which is important
 because social insects comprise a tremendous portion of global animal
 biomass, biodiversity, and ecosystem services. Considering how individual
 physiologies construct group-level adaptations can improve climate change
 impact assessments for social species. Tetragonisca angustula is a
 neotropical stingless bee species that exhibits high worker subcaste
 specialization with a morphologically distinct soldier caste. We used this
 species to investigate 1) whether age- and size-differentiated subcastes
 differ in thermal tolerance, 2) which worker subcaste operates closest to
 their thermal limits, and 3) the extent to which this species selects
 active foraging times to offset thermal stress. We measured the thermal
 tolerance (CTmax and CTmin) of small-bodied foragers and two soldier
 subcastes (hovering guards and standing guards) in T. angustula. Despite
 body size differences between foragers and guards, no differences in the
 upper or lower thermal limits were observed. However, the average thermal
 tolerance breadth of foragers was significantly larger than that of
 guards, and foraging sites were more thermally variable than nest sites,
 supporting the Climatic Variability Hypothesis at a microclimate scale and
 in the context of division of labor. Warming tolerance was significantly
 lower among small-bodied foragers compared to hovering and standing
 guards. The magnitude of warming tolerances indicated low risk of imminent
 climate change impacts in this environment but suggests that increasing
 temperatures and heatwave prevalence may cause foragers to meet their
 upper thermal limits before other subcastes. Foraging occurred at a
 narrower range of temperatures than would challenge critical temperatures,
 with higher morning activity. Directionally increasing temperatures will
 likely confine these preferred foraging temperatures to a narrower time
 window. Further study is needed to elucidate how foragers may shift times
 of activity in response to anthropogenic warming, but changing climates
 may impact plant pollination rates in natural and agricultural systems.
description: # Data from: Stingless bee foragers experience more thermally stressful
 microclimates but have wider thermal tolerance breadths than other worker
 subcastes
 [https://doi.org/10.5061/dryad.0k6djhb7s](https://doi.org/10.5061/dryad.0k6djhb7s) ## Description of the data and file structure The uploaded files include two printable 3D designs of iButton housings as well as all datasets used in our analyses. Detailed descriptions of each file are provided below. Temperature is in degrees Celsius. ### Dataset - T ang CT assay Foragers (F), standing guards (S), and hovering guards (H) from 10 colonies underwent either a CTmax or a CTmin assay (indicated by the header "Assay") to assess for within-colony differences in thermal tolerance. Not all individuals were run simultaneously which is indicated by the column header "Batch". "Coma" indicates the temperature at which the individual lost mobility. "CT" indicates the critical temperature defined as the most extreme temperature at which the individual retains mobility. "Environmental_high_temp" is the average daily high temperature recorded at each corresponding nest or the average across foraging sites for the foragers (for bees in the CTmax assay). "Warming_tolerance" is the difference between the CTmax and the environmental high temperature (for bees in the CTmax assay). Dry mass for each bee at a resolution of 0.1 mg is also reported in the column "Dry_mass_mg." ### Dataset - Thermal Breadth Because no one bee experienced both a CTmax and CTmin assay, the thermal tolerance breadth was calculated for each subcaste within each colony by subtracting the average CTmin from the average CTmax. Subcastes were foragers (F), standing guards (S), and hovering guards (H). ### Dataset - Hourly Site Temp Data Temperatures were recorded by iButtons for a full day (0000-2359), every 15 minutes, outside of each nesting site (n=13) and each foraging site (n=3) in 2023. This dataset shows the average of the 4 values logged within each hour. For "Site_Type", "F" indicates foraging sites, and "N" indicates nesting sites.  ### Dataset - Nest Activity with Temp Measure The activity of the different subcastes was measured at 6 colonies in 2022. "Time_num" is a conversion of the time of each recording period to numbers with decimals. "F_leaving_per_min" was the number of foragers exiting the nest entrance tube per minute. "F_arriving_per_min" was the number of foragers entering the nest entrance tube from outside the nest. "Hovering_G_avg" is the average number of hovering guards calculated from three counts over one minute. "Standing_G_avg" is the average number of standing guards calculated from three counts over one minute. "Nest_tube_temp" is the temperature of each nest tube measured via a thermocouple wire. "Wind" is a value from 0-5 based on the Beaufort Wind Scale as a rough approximation of wind conditions. "iButton_Temp" is the temperature at the nest entrance in degrees Celsius, as measured by an iButton. ### Dataset - Colony Data This includes general information for all colonies included in the aforementioned datasheets. "Cavity_type" is whether the nest was located in a natural object such as a tree cavity compared to a manmade object such as a cinder block. The "Entrance_length_cm" and "Entrance_diameter_mm" are measurements of the resinous tube that is the entrance to each nest. These measures are variable since the bees will modify them when they are damaged after raids, storms, or other physical interference. It is noted whether each nest was sampled for the data collected in 2022 compared to whether they were sampled in 2023. "Lat_coordinates" and "Long_coordinates" show the coordinates of each nest in decimal degrees. ### STL file - HousingV6 Printable 3D design for the ibutton housing used in this study. ### STL file - AdaptorV6 Printable 3D design for the ibutton adapter used in this study.