Data for: Clear effects of population and sex but not rearing temperature on stress tolerance in a temperate butterfly
Data files
Jun 13, 2025 version files 70.36 KB
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Fall21_CAT_AL_PostDiapause_Compiled.csv
65.33 KB
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README.md
5.03 KB
Abstract
With temperatures rising globally due to climate change, an organism’s survival depends both on its direct tolerance to rising temperatures and its tolerance to indirect effects of warming, such as resource shortage. Genetic background and phenotypic plasticity in the form of acclimation are known to affect stress tolerance, but much about genetic variation in plasticity is still unknown, especially in insects other than Drosophila. Here we aim to study the effect of population of origin, developmental temperature, and their interaction on heat and starvation tolerance. We test the beneficial acclimation hypothesis and how it is influenced by intraspecific differences. For this, we reared Glanville fritillary butterfly (Melitaea cinxia) larvae originating from Finland, where the climatic conditions experienced are relatively cool, and Spain, where the climate is relatively warm, at high and standard temperatures. In the adult stage, we measured stress tolerance as the time until heat knockdown at a constant 45 °C and lifespan under resource limitation. To assess other effects of thermal acclimation, we also measured performance traits such as larval developmental time, survival, and adult lifespan. We found no significant effect of rearing temperature on heat or starvation tolerance, and heat tolerance also did not differ directly between sex or population of origin. In contrast, we found interacting effects of population and sex on adult starvation tolerance, with females originating from Spain outperforming other groups. Spanish female butterflies also had a longer lifespan under non-stressful conditions, and we found significant GxE interactions in other performance traits. Even though our study provides no clear evidence for the beneficial acclimation hypothesis, it highlights the importance of considering population and sex differences in stress tolerance. Recognising these differences will help to fine-tune and prioritise conservation efforts.
https://doi.org/10.5061/dryad.6m905qg9v
Description of the data and file structure
Data on a rearing experiment in Melitaea cinxia performed on two populations at two temperatures, with three adult treatments. The experiment was performed in autumn 2021 in Helsinki, Finland, by Nadja Verspagen
Files and variables
File: Fall21_CAT_AL_PostDiapause_Compiled.csv
Description:
Variables
- Population: Population of origin. Al = Åland (Finland), CAT = Catalonia (Spain).
- Female ID: ID (running number) of the mother of the larvae, also referred to as family
- Clutch ID: ID (running number) for the egg clutch from which the larvae originate
- Temperature: Experimental temperature in degrees Celsius, either 34 (34 during the day and 21 during the night, this is the hot treatment) or 28 (28 during the day and 15 during the night, this is the control treatment)
- Replicate: Larvae from one clutch were divided over 3 replicate boxes: A, B, and C.
- Waking date: Date that the larvae were taken from the diapause chamber. After that, they were kept together in boxes at 25 degrees Celsius during the day and 8 during the night for 3 days, after which they were separated into the experimental treatments
- Group starting mass: Mass of the larval rearing group (g) at the start of the experiment.
- Individual starting mass: Group starting mass (g) / N.
- Pupal ID: Unique ID for each pupa (running number). When hardened, the pupa was removed from the larval rearing box, given a unique ID number, and placed in an individual cup. Some larvae died before pupation. These have been left in the dataset for mortality analysis, but given NA values for all pupal and adult columns in the dataset.
- Pupal date: Date that the pupa was weighed. This was always in the morning, and only "dry" enough pupae were taken (others were left for the next day).
- Pupal mass: Mass of the pupa (g). Some larvae did not survive until pupation.
- Adult ID: ID for each adult (running number). This is a running number per population, because large numbers do not fit on the wing. Together with the Population, this is a unique ID to identify each individual. Some individuals died during the pupal stage and did not eclose. These have been given NA values for all adult columns in the dataset.
- Eclosion date: Date of butterfly eclosion from the pupa. All pupae were checked at 15:00 latest, meaning that individuals that eclosed after this time were registered the next day. However, the vast majority of butterflies eclosed in the morning.
- Sex: M = male, F = female
- Adult treatment: At eclosion, butterflies were randomly assigned to an adult treatment by lottery ticket. CF = "control food" (butterflies were moved to the greenhouse and fed daily), NF = "no food" (butterflies were moved to the greenhouse and fed only for 6 hours at day 3 after eclosion, for the rest they have access to water) and HT = "heat tolerance" (butterflies were moved to the greenhouse and used in heat tolerance assays 3 days after eclosion.
- Dead date: Only for CF and NF butterflies, the dead date was recorded every morning to calculate adult lifespan. HT butterflies were used in the heat tolerance assays, resulting in NA values in this column.
- Test date: Date of thermal tolerance tests. This was always 3 days after eclosion. Butterflies were taken from the greenhouse in the morning and kept with a piece of wet cotton in the dark until the start of the test. Tests were only performed in HT butterflies, resulting in NA values for the other groups.
- Start time: Time when the butterfly entered the test jar. Tests were only performed in HT butterflies, resulting in NA values for the other groups.
- KO time: Time at the stopwatch when the butterfly was declared KO. When a butterfly stopped moving, it was poked. If no movement was recorded within 30 seconds after poking, it was declared KO and the initial time of no movement was recorded. Tests were only performed in HT butterflies, resulting in NA values for the other groups.
- Position: Position in the heat tolerance setup tank. Tests were only performed in HT butterflies, resulting in NA values for the other groups.
- Notes: Notes. Notes were only taken in special cases, so most cells will contain NA values.
Some cells contain NA values. This can have several reasons:
- The individual died during the larval stage (all pupal and adult columns will be NA).
- The individual died during the pupal stage (all adult columns will be NA).
- The dead date column contains additional NAs for individuals from the HT treatment.
- Columns for the heat tolerance assays contain additional NAs for individuals from the CF and NF treatments.
- Notes contain mostly NAs because a note was only taken on special occasions.
Code/software
The R code used to analyse this data is attached