Silk-borne chemicals of spider nuptial gifts elicit female gift acceptance

Abstract

Chemical communication is important in a reproductive context for conveying information used for mate recognition and/or assessment during courtship and mating. Spider silk is a common vehicle for chemical communication between the sexes. However, despite being well described in females, male silk-borne chemicals remain largely unexplored. Males of the spider Pisaura mirabilis silk-wrap prey (i.e. nuptial gifts) that is offered to females during courtship and eaten by the female during mating. Interestingly, rejected males often add more silk to their gift which leads to successful mating, suggesting the presence of silk-borne chemicals that facilitate female gift acceptance. To test this hypothesis, we offered females standardized gifts covered with male silk that was either washed in solvents or unwashed, respectively, to remove or not any chemically active components. We scored female gift acceptance, and as expected in the case chemicals that mediate female mating behaviour are present in male silk, females were more likely to accept gifts covered with unwashed silk. Our findings suggest that silk-borne chemicals of nuptial gifts prime female responses, potentially signalling male quality or manipulating females into mating beyond their interests given the occurrence of male cheating behaviour via nutritionally worthless gifts in this system.

Strands of Connection: Livestock Grazing, Vegetation Density, and Orb-Weaver Spider Persistence

“…In this case, the species would need some chemical, physiological or mechanical mechanism to identify the plants. Spiders have a complex chemical communication system that involves pheromones for mate and offspring recognition (Guimarães et al 2018;Fischer et al 2019;Beyer et al 2021). However, few authors suggest the attractiveness of plant chemicals for spiders (Fischer et al 2018(Fischer et al , 2019(Fischer et al , 2021.…”

Host Plant Specificity in Web-Building Spiders

“…The alternative to the random or systematic search strategies for finding suitable plant hosts discussed above is a more targeted strategy using chemical cues. Spiders are known to use chemical cues in sexual communication, especially in relation to males locating females through silk-borne [ 123 ] or cuticular cues [ 124 ]. We refer readers to the recent excellent review by Fischer [ 19 ] on chemical communication in spiders focusing on a methodological overview on how to study their pheromones.…”

The loss of nuptial gifts in sclerosomatid Opiliones coincides with increased behavioural sexual conflict

“…Nuptial gift production can increase male mortality (Małek et al 2019; Perry & Tse 2013) and reduce male courtship quality (del Castillo & Gwynne 2007), and even simply carrying nuptial gifts can significantly increase male energy expenditure (Prokop & Okrouhlik 2021). Both endogenous fluid and exogenous prey have high production demands which often leads to selective pressures to maximise the gift efficiency and efficacy through various strategies, including deceiving females or plastically altering gifts in response to female quality (Albo et al 2019; Beyer et al 2021; Ghislandi et al 2018; Martínez-Villar et al 2023; Pandulli-Alonso et al 2021; Solano-Brenes et al 2021; Stålhandske 2002).…”