DOI: 10.5061/dryad.tht76hf4r
title: Data from: Extreme heat reduces host and parasite performance in a butterfly-parasite interaction

description: Environmental temperature fundamentally shapes insect physiology, fitness,
 and interactions with parasites. Differential climate warming effects on
 host versus parasite biology could exacerbate or inhibit parasite
 transmission, with far-reaching implications for pollination services,
 biocontrol, and human health. Here, we experimentally test how controlled
 temperatures influence multiple components of host and parasite fitness in
 monarch butterflies (Danaus plexippus) and their protozoan parasites
 Ophryocystis elektroscirrha. Using five constant temperature treatments
 spanning 18-34°C, we measured monarch development, survival, size, immune
 function, and parasite infection status and intensity. Monarch size and
 survival declined sharply at 34°C, as did infection probability,
 suggesting that hot temperatures decrease both host and parasite
 performance. The lack of infection at 34°C was not due to greater host
 immunity or faster larval development but could instead reflect the
 thermal limits of parasite invasion and within-host replication. In the
 context of ongoing climate change, our experiment suggests that
 temperature increases above the upper thermal range will reduce the
 fitness of both monarchs and their parasites, with lower infection rates
 potentially mitigating the impact of extreme heat on future monarch
 abundance and distribution.
description: We used a constant temperature experiment to explore how
 temperature influences components of host and parasite performance in
 monarch butterflies (Danaus plexippus) and their protozoan parasite OE
 (<em>Ophryocystis elektroscirrha</em>). In lab incubators, we
 used five constant temperature treatments spanning 18-34°C to measure
 monarch development, survival, size, immune function, and OE infection
 status and intensity. Data was entered using Excel and
 analyzed in R Studio.
description: R and R Studio are required to open the data files included.
description: # Extreme heat reduces host and parasite performance in a
 butterfly-parasite interaction
 This file contains three
 datasets describing monarch performance and parasite infection outcomes
 across a gradient of five constant temperatures along with the code used
 to perform statistical analysis. ## Description of the data and file
 structure File: mtemp_comp_Nov1_2021.csv This file contains a row for each
 individual monarch "ID," with columns on the temperature
 treatment, host genetic lineage, and parasite strain used (if inoculated).
 For each monarch, there are data on key dates in the experiment (e.g. date
 inoculated, date of death), monarch performance metrics, and infection and
 intensity measures. Cells for traits that were not measured for an
 individual contain "NA". This file is used for the majority of
 analysis, including generalized additive models and generalized linear
 models of traits across temperature. File: Hemocyte_counts_June5.csv This
 file contains raw hemocyte counts for hemocytomer chambers along with
 counts of specific immune cell types. Additional columns include the
 hemocyte concentrations (per microliter of hemolymph), log base 10
 transformed concentration, and proportions of each of the four immune cell
 types. Cells with NA for hemocytes correspond to hemocytometer chambers
 that were not measureable (most often due to melanization or lipid
 contamination). A few larvae and pupae were not massed, so their Mass is
 listed as NA. File: Merozoites_7_21.csv This file contains average number
 of of internal parasite stages (merozoites) per hemocytometer chamber for
 viable pupal hemolymph samples. Additional columns contain the merozoite
 concentrations (per microliter of hemolymph) and log base 10 transformed
 concentration. A few pupae were not massed, so their Mass is listed as NA.
 Column names defined: "ID" = uniquie monarch identification
 number (1-450)\ "Temp" = Temperature treamtment (18, 22, 26, 30,
 34)\ "Lineage" = One of three outbred host lineages (B, D, F)\
 "OE_strain" = Parasite treatment (control, E3, or E10)\
 "Inoculation" = date fed inoculation leaf (all monarchs were
 inoculated outside of incubators - except for a few that took &gt;24 hours
 to consume the inoculum)\ "Into_pint" = date put into an
 individual pint within the incubator\ "Bleed_stage.x" = assigned
 stage to be sampled for hemolymph (None, Larva, Pupa)\
 "Bleed_date.x" = date hemolymph taken\ "Death_date" =
 date died (most entries have notes on stage at death)\
 "Pupation_date" = date pupated (either as J splitting skin or
 completed pupa)\ "Eclosion_date" = date adult emerged\
 "Surv_pupa" = binary survival to pupal stage (1,0)\
 "Surv_adult" = binary survival to adult stage (1,0)\
 "Wing_deformity" = score of how deformed wings are (0 = no
 deformity to 3 = extremely deformed) (made binary with 2 or 3 as deformed
 for analysis)\ "Adult_death_date" = date of adult death\
 "Sex" = Male or female (for all individuals surviving to
 adulthood)\ "Infection_status" = binary infected or not (1,0)\
 "OE_score" = infection intensity from tape samples (0 to 5)\
 "Dev_pupa" = time to pupation (days)\ "Dev_adult" =
 time to adult emergence (days)\ "Adult_longevity" = lifespan as
 an adult (death - emergence)(days)\ "NOTES" = any notes on
 individual during experiment\ "Bleed_date.y" = date hemolymph
 taken (from hemolymph datasheet)\ "Who" = researcher who counted
 hemocytes\ "Bleed_stage.y" = stage actually sampled for
 hemolymph (None, Larva, Pupa) (from hemocyte datasheet)\ "Mass"
 = mass of some larvae and pupa (only for subset of bled individuals) (g,
 from hemocyte datasheet)\ "AvgHemo" = average number of
 hemocytes in one chamber of kova hemocytometer slide (from hemocyte
 datasheet)\ "Hemo_ul" = hemocytes per microliter (AvgHemo*10)
 *(from hemocyte datasheet)*\ *"LogHemo" = Log base 10 of
 (Hemo_ul +1) (from hemocyte datasheet)*\ *"PropPlasm" =
 proportion of hemocytes that were classified as plasmatocytes (out of
 first ~100 cells in kova chambers (or all cells in kova chambers if
 &lt;100) (from hemocyte datasheet)*\ *"PropOeno" = proportion of
 hemocytes that were classified as oenocytoids (out of first ~100 cells in
 kova chambers (or all cells in kova chambers if &lt;100) (from hemocyte
 datasheet)*\ *"PropSpher" = proportion of hemocytes that were
 classified as spheroids (out of first ~100 cells in kova chambers (or all
 cells in kova chambers if &lt;100)(from hemocyte datasheet)\
 "PropGran" = proportion of hemocytes that were classified as
 granulocytes (out of first ~100 cells in kova chambers (or all cells in
 kova chambers if &lt;100)(from hemocyte datasheet) "Initials" =
 researcher who counted vortexing slides for spore load*\ *"Date"
 = date sample vortexed for spore load analysis*\ *"AvgOE_count"
 = average number of OE spores in one chamber of kova hemocytometer slide*\
 *"Spore_load" = OE spores per monarch (AvgOE_count*10 (OE per
 ul) and * 5000 as monarchs were vortexed in 5mL of water)\
 "logSpore_load" = Log base 10 of (Spore_load +1)\
 "Area" = total wing area in mm^2\ "Length" = Wing
 length in mm\ "Breadth" = Wing width in mm\
 "AspectRatio" = Wing length / breadth (measure of wing
 elongation - migratory wings typically more elongated) - not used in
 analysis\ "FinalAbsorbance" = Phenoloxidase assay absorbance
 value at the final timestep (from BioTek microplate reader software) ##
 Sharing/Access information Data and code can also be accessed on GitHub: *
 
 Resources we found helpful: *
 [https:/noamross.github.io/gams-in-r-course/](https://noamross.github.io/gams-in-r-course/) * [https:/jacolienvanrij.com/Tutorials/GAMM.html](https://jacolienvanrij.com/Tutorials/GAMM.html) ## Code/Software Statistical analyses were completed in R (v. 4.0.5). Code was implemented using loaded packages: *tidyverse, ggplot2, lme4, visreg, plyr, mgcv, MASS, itsadug,* and *sjPlot.* File: GAM_temp2019_Jul24_2023.rmd This R markdown file contains generalized additive model analysis of control monarch performance, performance of infected vs. uninfected monarchs, and infection outcomes. Also contains the linear model assessing whether monarch tolerance to infection varied among temperature treatements. File: GAM_temp2019_Nov26_2023.rmd\ This R markdown file is an updated version of the above file from July. This version includes analyses on the subset of infected monarchs assessing whether there are parasite strain-specific effects on monarch performance metrics across temperature. File: GLM_immuneTradeoffs_2019.rmd This R markdown file contains generalized linear model analysis of tradeoffs between monarch immunity and fitness measures or infection outcomes along with generalized additive models for immune cell proportions across temperature. File: MonarchOE_Temperature_Infection2019-main.Rproj is the R project that bundles the relevant scripts and data files used for the analysis. Save project file in the same folder as markdown files and a folder named "data" the holds the three .csv files. Open the project in R Studio and then access the markdown files within the project.