DOI: 10.5061/dryad.ksn02v7jb
title: Earwig mothers employ a suite of hygienic behaviors to defend their nest against microbial threats

description: 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.
description: # Earwig mothers employ a suite of hygienic behaviors to defend their nest
 against microbial threats Dataset DOI:
 [10.5061/dryad.ksn02v7jb](https://doi.org/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