0000000000646218
AUTHOR
Maximilian Körner
Growing up with feces: benefits of allo-coprophagy in families of the European earwig
International audience
When earwig mothers do not care to share: Parent–offspring competition and the evolution of family life
Kin competition often reduces – and sometimes entirely negates – the benefits of cooperation among family members. Surprisingly, the impact of kin competition on the fitness effects of family life only received close scrutiny in studies on sibling rivalry, whereas the possibility of parent–offspring competition has attracted much less attention. As a consequence, it remains unclear whether and how parent–offspring competition could have affected the early evolution of parental care and family life. Here, we examined the occurrence and consequences of parent–offspring competition over food access in the European earwig Forficula auricularia, an insect with facultative family life reminiscent…
Feces production as a form of social immunity in an insect with facultative maternal care
Background Social animals have the unique capability of mounting social defenses against pathogens. Over the last decades, social immunity has been extensively studied in species with obligatory and permanent forms of social life. However, its occurrence in less derived social systems and thus its role in the early evolution of group-living remains unclear. Here, we investigated whether lining nests with feces is a form of social immunity against microbial growth in the European earwig Forficula auricularia, an insect with temporary family life and facultative maternal care. Results Using a total of 415 inhibition zone assays, we showed that earwig feces inhibit the growth of two GRAM+ bact…
Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life
Offspring of species with facultative family life are able to live with and without parents (i.e. to adjust to extreme changes in their social environment). While these adjustments are well understood on a phenotypic level, their genetic underpinnings remain surprisingly understudied. Investigating gene expression changes in response to parental absence may elucidate the genetic constraints driving evolutionary transitions between solitary and family life. Here, we manipulated maternal presence to observe gene expression changes in the fat body of juvenile European earwigs, an insect with facultative family life. Because parents typically protect offspring against pathogens, expression chan…
Condition-Dependent Trade-Off Between Weapon Size and Immunity in Males of the European Earwig
Abstract Investigating the expression of trade-offs between key life-history functions is central to our understanding of how these functions evolved and are maintained. However, detecting trade-offs can be challenging due to variation in resource availability, which masks trade-offs at the population level. Here, we investigated in the European earwig Forficula auricularia whether (1) weapon size trades off with three key immune parameters – hemocyte concentration, phenoloxidase and prophenoloxidase activity - and whether (2) expression and strength of these trade-offs depend on male body condition (body size) and/or change after an immune challenge. Our results partially confirmed conditi…
Social immunity: why we should study its nature, evolution and functions across all social systems.
Mounting defences against pathogens is a necessity for all animals. Although these defences have long been known to rely on individual processes such as the immune system, recent studies have emphasized the importance of social defences for group-living hosts. These defences, called social immunity, have been mostly studied in eusocial insects such as bees, termites and ants, and include, for instance, mutual cleaning and waste management. Over the last few years, however, a growing number of works called for a broader exploration of social immunity in non-eusocial species. In this review, we summarize the rationales of this call and examine why it may provide major insights into our curren…
Extended winters entail long-term costs for insect offspring reared in an overwinter burrow
International audience; Winter imposes an ecological challenge to animals living in colder climates, especially if these adverse conditions coincide with reproduction and offspring rearing. To overcome this challenge, some insects burrow in the soil to protect adults, larvae, or eggs from negative effects of winter. However, whether this protection is effective against any long-term consequences of changes in winter duration is unclear. Here, we investigated the long-term effects of winter length variation on eggs of the European earwig Forficula auricularia. In this insect, females construct and maintain a burrow between late autumn and spring, in which they provide extensive forms of care…
Data from: Growing up with feces: benefits of allo-coprophagy in families of the European earwig
An important issue in the evolution of group living is the risk of pathogen and predator exposure entailed by the inherent accumulation of feces within a nesting site. While many group living species limit this risk by cleaning the nest, others do not, raising questions about the benefits of maintaining feces in the nest and their importance in social evolution. Here, we investigated whether one of these benefits could be mediated by coprophagy in families of the European earwig, Forficula auricularia. In this insect species, mothers and mobile juveniles (nymphs) line their nests with feces and consume them. In a first experiment, we tested whether access to feces produced by either nymphs …
Data from: When earwig mothers do not care to share: parent-offspring competition and the evolution of family life
1. Kin competition often reduces – and sometimes entirely negates – the benefits of cooperation among relatives, and hence is often regarded as central process in social evolution. Surprisingly, however, our understanding of the role of kin competition in the evolution of family life remains fragmentary, despite the close scrutiny it received in studies on sibling rivarly. This is because much less attention has been given to local competition between parents and their offspring, and its potential impact on the early evolution of parental care and family life. 2. Here, we examined mother-offspring competition over food access in the European earwig Forficula auricularia, an insect with facu…
Figure S1 from Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life
Genes affected by the presence of the pathogen, independently of maternal presence. Y-axis represents normalized expression across samples per gene (Z-Score).
Tables S1 & S2 from Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life
Table S1. Comparisons of different transcriptome assemblies. The table on the sheet "Transrate output" shows data obtained using Transrate v.1.03 (Smith-unna et al., 2016). We compared assemblies created using Trinity and CLC Assembly Cell, as well as a merged "hybrid" obtained using CAP3 (Huang and Madan, 1999). The assembly comparison was used to determine the best assembly for continued analyses. Table S2. Full list of all DEGs revealed by the LRTs testing for main and interaction effects, as well as the associated annotations and read counts per sample. Note that no DEGs depended on maternal presence alone. Table headers are default DEseq2 headers, while the Blast annotation was added b…