Microbial symbiont performance under thermal stress does not predict vector competence
Data files
Feb 10, 2026 version files 346.62 KB
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Adult_weight_data.csv
16.28 KB
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Code.r
105.09 KB
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Development_time_data.csv
123.17 KB
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Mortality_data.csv
5.42 KB
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README.md
5.77 KB
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Serratia_Colony_Counts.csv
17.40 KB
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Strain_growth_curves_data.csv
73.50 KB
Abstract
Insect-microbe symbioses are critical to host development, immunity, and ecological interactions, including pathogen vectoring. The squash bug Anasa tristis is an agricultural pest and vector of Serratia ureilytica, the agent of Cucurbit Yellow Vine Disease. This insect hosts an environmentally acquired Caballeronia symbiont that aids development and suppresses pathogen load. While different Caballeronia strains appear functionally equivalent under benign conditions, they differ in thermal tolerance. It is unknown whether host thermal stress influences symbiont-mediated suppression of S. ureilytica. We evaluated whether elevated temperature affects the ability of different symbiont strains to influence pathogen titer and host performance. We measured development, adult weight, survival, and S. ureilytica counts in A. tristis reared with different symbiont strains from 24–36ºC. Thermal stress affected host performance in a strain-dependent manner, with some symbionts conferring greater survival at high temperatures. Surprisingly, pathogen suppression did not vary with symbiont strain or host rearing temperature. These results suggest that while symbiont identity modulates host performance under thermal stress, these effects do not alter pathogen load or transmission potential. Instead, the symbiont may initiate some host immune responses. This work underscores the context-dependent nature of symbiont-pathogen interactions and the importance of disentangling environmental effects on vector competence.
Description of the data and file structure
This README file describes the data packages and code accompanying the above publication.
Files and variables
File: Adult_weight_data.csv
Description: Fresh weight of adult A. tristis across three temperature treatments, colonized by one of four Caballeronia isolates or reared aposymbiotically, and either exposed to Serratia or not. Each row represents a single insect.
Variables
- BoxID: The cage in which an insect was reared.
- BugID: Unique identification letter for each insect in a box. Letter was provided upon collection at adulthood.
- Date: The date the insect was collected from its rearing cage.
- Strain: Identity of the Caballeronia a host was infected with.
- Serratia: Does not have Serratia (0) or has Serratia (1).
- Temp: The temperature in Celsius at which the insects were reared.
- Weight(mg): Fresh weight in mg upon eclosion to adulthood.
- Sex: Male (M), female (F), unidentified (X).
- Status: Collected as a live adult (L), alive but failed to molt (F), died before collection (D).
- Notes: Any notes about the individual. NA if there were no notes.
File: Strain_growth_curves_data.csv
Description: Serratia thermal growth curves subjected to five temperature treatments. Every row represents the maximum growth slope for one replicate per strain.
Variables
- sid: Identity of the Serratia isolate.
- rep: replicate number for the specified strain.
- temp: The temperature in Celsius at which the strain was grown.
- well: The plate well the culture was grown in.
- slope: Maximum growth slope.
- slope_lwr: Lower limit of the growth slope.
- slope_upr: Upper limit of the growth slope.
- intercept: Intercept of the growth curve region.
- rsq: R-squared value of the growth curve region.
- ln_od: Natural log of the optical density of the maximum growth curve region.
File: Serratia_Colony_Counts.csv
Description: Serratia CFU/mL per A. tristis whole bug homogenate. Insects were subjected to three temperature treatments and provided with Serratia after Caballeronia infections. Every row represents one insect.
Variables
- Date: The date the plate was counted (48 h after plating).
- PlateID: The specific ID for the insect dilution plate.
- Strain: Identity of the Caballeronia a host was infected with.
- temperature: The temperature in Celsius at which the insects were reared.
- timepoint: Days post 48 h Serratia infection.
- iteration: The iteration of the plating experiment.
- cfu/ml_count: Serratia titer in CFU (colony forming units) per mL.
- has_Serratia?: Whether the insect had Serratia (cfu/ml_count > 0)
File: Mortality_data.csv
Description: Host survival of A. tristis across three temperature treatments, colonized by one of four Caballeronia isolates or reared aposymbiotically, and either exposed to Serratia or not. Every row represents survival for each cage.
Variables
- boxid: The cage in which an insect was reared.
- strain: Identity of the Caballeronia a host was infected with.
- serratia: Does not have Serratia (0) or has Serratia (1).
- temp: The temperature in Celsius at which the insects were reared.
- live3: The number of live third instars.
- dead3: The number of dead third instars.
- live4: The number of live fourth instars.
- dead4: The number of dead fourth instars.
- live5: The number of live fifth instars.
- dead5: The number of dead fifth instars.
- live6 : The number of live adults. Insects were collected and removed from the cages at this point.
- totallive: Total number of insects alive in the cage. Includes adult insects that were removed during observations.
- totaldead: Total number of insects that died in the cage. Includes all insects that died over the course of all observations.
- totalbugs: Total number of insects in the cage. Includes adults and dead insects that were removed when found during daily observations.
File: Development_time_data.csv
Description: Development times of A. tristis across three temperature treatments, colonized by one of four Caballeronia isolates or reared aposymbiotically, and either exposed to Serratia or not.. Every row represents one daily data collection for each cage.
Variables
- boxid: The cage in which an insect was reared.
- date: The date of data collection
- strain: Identity of the Caballeronia a host was infected with.
- serratia: Does not have Serratia (0) or has Serratia (1).
- temp: The temperature in Celsius at which the insects were reared.
- live3: The number of live third instars.
- dead3: The number of dead third instars.
- live4: The number of live fourth instars.
- dead4: The number of dead fourth instars.
- live5: The number of live fifth instars.
- dead5: The number of dead fifth instars.
- live6 : The number of live adults. Insects were collected and removed from the cages at this point.
- Notes: Any notes about the cage. Start indicates initial observation for cage, retire indicates final observation, NA if there were no notes.
- totallive: Total number of insects alive in the cage. Includes adult insects that were removed during observations.
- totaldead: Total number of insects that died in the cage. Includes all insects that died over the course of all observations.
- totalbugs: Total number of insects in the cage. Includes adults and dead insects that were removed when found during daily observations.
File: Code.r
Description: R code used to generate the figures and analyze data. Also it fits linear mixed‐effects models to insect weight data across temperatures and strains, then generates predicted values with confidence intervals.