Earwig mothers employ a suite of hygienic behaviors to defend their nest against microbial threats
Data files
Oct 07, 2025 version files 69.42 KB
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DataAfter.csv
32.28 KB
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DataBefore.csv
34.66 KB
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README.md
2.48 KB
Abstract
Hygienic behavior is a key defense against pathogens in mammals and birds, yet it remains surprisingly understudied in insects outside eusocial species. This gap raises the questions of whether such behaviors are unique to eusocial insects or instead reflect widespread forms of social immunity that may have shaped the evolution of insect sociality. Here, we investigated hygienic behavior in the European earwig, a non-eusocial insect exhibiting maternal egg care. First, we exposed pre-ovipositing females and males to organic (microbial risk) and plastic items, and found that only females selectively covered organic items, starting at oviposition. We then introduced either an organic item, an organic item with pathogen spores, a plastic item, or no item into female nests post-oviposition. Mothers continued to cover organic items and consistently relocated their eggs away from them, regardless of the presence of pathogen spores. Nest architecture remained unaffected by item type. Altogether, these findings reveal advanced hygienic behaviors in a non-eusocial insect, confirming that certain forms of social immunity can evolve independently of eusociality and reproductive division of labor. These findings highlight how parental care could have been a pivotal step in the evolutionary trajectory toward the sophisticated disease defenses seen in more complex insect societies.
Dataset DOI: 10.5061/dryad.ksn02v7jb
Description of the data and file structure
The data is composed of two CSV files: DataBefore.csv and DataAfter.csv, containing respectively the data before oviposition and after oviposition.
Files and variables
File: DataAfter.csv
Variables
- ID: Identification of the individual
- Treatment: The nature of the item (Food, Metarhizium: Food + Metarhizium brunneum, Plastic, Control: No item)
- Date_laying_J: The number of days between the first oviposition observed among the females of the experiment and the oviposition of the current individual
- Nb_eggs: Number of eggs laid by the individual
- Date_eclosion_J: Number of days between eclosion and oviposition of the clutch
- nb.day.hatching: Calendar hatching timing: Number of days between eclosion and oviposition of the first clutch of all females
- Nb_nymphe: Number of nymphs produced by the individual
- disp_eggs: Measure of egg relocation relative to their position one week before, in millimeters
- Cover: Percentage of items covered with substrate by the individual one week after the placement of the item (visually inspected and determined if it was 0% covered or approximately 25%, 50% ,75% or 100% covered)
- Nest_complexity: Measure of nest wall construction by the individual (more the number is high, more complex the nest is, 0 means No construction, 4 means a large cavity with high walls of sands)
- dist_eggs_obj: Distance between the item and the eggs one week after the placement of the item, in millimeters
- Week: Number of the week after the first placement of the item
NA cells are empty cells with no value available
File: DataBefore.csv
Variables
- ID_isolation: Identification of the individual
- SEXE: Sex of the individual (F for females and M for males)
- Treatment: The nature of the item (Control, Plastic, Food, Metarhizium)
- Week.precise: The timing of the measurement relative to the oviposition date in weeks when a "w" is at the end ("-5w" means "5 weeks before oviposition") or in days when a "d" is at the end ("3d" means "3 days after oviposition")
- Cover.bin: The covering status of the item one week after its placement (1: At least 25% of the item is covered; 0: Less than 25% of the item is covered)
NA cells are empty cells with no value available