Relationship between weapon size and six key behavioural and physiological traits in males of the European earwiguse asterix (*) to get italics

Samantha E.M. Blackwell, Laura Pasquier, Simon Dupont, Séverine Devers, Charlotte Lécureuil, *Joël Meunier Please use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"

2024

<p style="text-align: justify;">In many animals, male weapons are large and extravagant morphological structures that typically enhance fighting ability and reproductive success. It is generally assumed that growing and carrying large weapons is costly, thus only males in the best condition can afford it. In the European earwig, males carry weapons in the form of forceps-like cerci, which can vary widely in size within populations. While long forceps appear to increase male’s access to females, it is unknown whether it also correlates with other important male life-history traits. This information is important, however, in determining the potential reliability of forceps length as an indicator of male quality and the stability of this signalling system. Here, we tested whether forceps length is associated with six important behavioural and physiological traits in males of the European earwig. We sampled hundreds of males from two populations, selected 60 males with the longest and shortest forceps from each population, and then measured locomotor performance, boldness, aggregation behaviour, survival under harsh conditions, sperm storage, and survival after pathogen exposure. Contrary to our predictions, we detected no main association between forceps length and the traits measured. This lack of association was consistent between the two populations, although there were population-specific levels of boldness, aggregation and survival in harsh conditions (for long-forceps males only). Overall, these results challenge our current understanding of the function and quality signal of forceps length in this species and raise questions about the evolutionary drivers that could explain the maintenance of weapon size diversity within and between populations.</p>

https://doi.org/10.5281/zenodo.11469628You should fill this box only if you chose 'All or part of the results presented in this preprint are based on data'. URL must start with http:// or https://

https://doi.org/10.5281/zenodo.11469628You should fill this box only if you chose 'Scripts were used to obtain or analyze the results'. URL must start with http:// or https://

Weapons; Forceps; Ornament; Sexual selection; Insect; Behaviour

NonePlease indicate the methods that may require specialised expertise during the peer review process (use a comma to separate various required expertises).

Behavior, Evolution, Insecta, Invertebrates, Life histories, Morphology

ErMcCullough@clarku.edu, Doug.Emlen@mso.umt.edu No need for them to be recommenders of PCI Zool. Please do not suggest reviewers for whom there might be a conflict of interest. Reviewers are not allowed to review preprints written by close colleagues (with whom they have published in the last four years, with whom they have received joint funding in the last four years, or with whom they are currently writing a manuscript, or submitting a grant proposal), or by family members, friends, or anyone for whom bias might affect the nature of the review - see the code of conduct

2024-03-26 08:56:27

Olivier Roux