DOI: 10.5061/dryad.kkwh70sb7
title: Osmia lignaria larval development response to heatwave treatments

description: Heatwaves are expected to increase in frequency, intensity, and duration
 due to climate change. For organisms like insects with discrete
 development, sensitivity may differ among life stages. Thermal sensitivity
 is of particular concern for species like bees that provide critical
 ecosystem services. Although social bees moderate nest temperatures
 through worker behavior, solitary bees do not thermoregulate their nests,
 making immobile developing offspring especially vulnerable to such extreme
 events. We studied the effects of heatwaves on larval development in the
 solitary bee, Osmia lignaria, an important orchard pollinator and
 model species for solitary bee biology. We used a factorial design to
 assess the impacts of heatwave temperature and duration on larval
 mortality and development rate. Larvae were exposed to heatwaves under
 realistic diel temperature regimes, with daytime maxima of 31˚C or 37˚C
 for four or seven days at the beginning of development. Heatwave
 temperature strongly affected larval mortality. Exposure to 37˚C heatwaves
 increased larval mortality by 130%, but the cooler 31˚C heatwaves did not
 significantly impact mortality. Heatwave duration did not impact larval
 mortality. Larval development time also was affected by heatwave exposure.
 Compared to the no-heatwave-control, bees in the 31˚C heatwave developed
 faster, and bees in the 37˚C heatwave developed slower. Our study reveals
 the importance of stage-specific effects of extreme events and suggests
 that the timing and maximum temperature of projected heatwaves may be more
 detrimental to populations than heatwave duration.
description: Data was collected by scoring larval development stage and
 mortality, after bees cocooned we weighed bees until emergence. Emergence
 date was also recorded. 
description: # Heatwaves increase larval mortality and delay development of a solitary
 bee
 [https://doi.org/10.5061/dryad.kkwh70sb7](https://doi.org/10.5061/dryad.kkwh70sb7) ## Authors: Grace G. Melone, Clara Stuligross, and Neal M. Williams. University of California, Davis ## Description of the data and file structure See methodology in associated manuscript. **heatwave_nov.csv**: NestNumber: individual nest which contained multiple bees BeeID: individually marked bee Treatment: integer value 1-5 indicating heatwave treatment: 1. Control 2. Low temperature, Short duration 3. Low temperature, Long duration 4. High temperature, Short duration 5. High temperature, Long duration DurationX: integer value 4 or 7, indicating short or long heatwave duration TemperatureX: integer value 25, 33, or 37, indicating control, low temperature heatwave, and high temperature heatwave temperatures, respectively. While temperature is marked as 33 in the data, the true temperature as indicated by temperature loggers in incubators was 31. DateCollected: Month/Day corresponding to the date completed nests were collected for the experiment Location: character value of NH or SH, corresponding to which hoop house nests were collected from Position: integer value indicating position in nest, where 1 was the first egg at the end of the nest bees would start from. EstimatedSex: integer value of 0 or 1 indicating estimated sex, with 0 indicating males and 1 indicating females. StageOnCollection: larval stage bees were in when nests were collected (0 as all bees used were in the egg stage) Instar1: integer value indicating the number of days from collection to develop to instar 1 Instar2: integer value indicating the number of days from collection to develop to instar 2 Instar34: integer value indicating the number of days from collection to develop to instar 3 or 4. Instar5: integer value indicating the number of days from collection to develop to instar 5. SpinStart: integer value indicating the number of days from collection to begin spinning cocoons. CocoonComplete: integer value indicating the number of days from collection to completing spinning of the cocoon. Mortality: integer value of 0 or 1, with 0 indicating bees survived and 1 indicating bees died before reaching the end of prepupal development. MortalityDate: month/day indicating the date bees died. DaystoDeath: integer value indicating the number of days from collection to mortality DeathStage: integer corresponding to larval stage at which bees died: 0\. egg 1. instar 1 2. instar 2 3. instar 3 4. instar 4 5. instar 5 Weight: fresh integer indicating fresh weight of bees in grams which completed cocoons, all bees were weighed in early July 2020 Weight_Sept: integer indicating fresh weight of bees in grams which completed cocoons in September of 2020 Weight_Nov: integer indicating fresh weight of bees in grams which completed cocoons in November of 2020 Notes: notes taken throughout the experiment **heatwave_emergence.csv** (includes all of the above data and emergence data, repeated columns not listed below): mortality_postlarv: integer value of 0 or 1; where 0 indicates survival and 1 indicates mortality DeathStage: integer value of 0-8; integers 0-5 described above 6\. prepupa 7\. pupa 8\. adult itd: blank column weight_feb: integer indicating fresh weight of bees in grams which completed cocoons in February of 2021 emergence: integer value of 0 or 1; where 0 indicates bees did not emerge and 1 indicates successful emergence emergence_date: mm/dd/yy date that bees emerged from their cocoons sex: character value of F or M; where F indicates females and M indicates males **Note on NAs/empty cells in the csvs**: empty cells indicate no data was recorded for that larva for that day, and have not been modified as to not affect code. After larvae died, no data was entered into the cells that would have contained days to each life stage or weight data. ## Sharing/Access information Links to other publicly accessible locations of the data: [https://github.com/gigi-melone/osmialignaria_heatwaves2023](https://github.com/gigi-melone/osmialignaria_heatwaves2023)