Pheromone communication among sexes of the garden cross spider Araneus diadematus

Andreas Fischer,Manfred Ayasse,Gabriele Uhl,Stefan Schulz

doi:10.1007/s00114-021-01747-9

Abstract

Chemical communication plays a fundamental role in many aspects of an animal’s life from assessing habitat quality to finding mating partners. Behavioural observations show that chemical communication likewise plays an important role in spiders, but the contexts and the substances involved are little explored. Here, we investigate the chemical communication in the garden cross spider Araneus diadematus (Clerck, 1757) between and within the sexes. Using choice trials, we demonstrate that males are attracted to odours of adult females, but not to those of subadult females. Our data further suggest that adult females avoid odours of conspecific adult females, possibly in order to reduce reproductive competition with other females. Cuticle and silk extracts as well as headspace samples of subadult and adult virgin females were analysed via GC–MS. Available candidate compounds for the female sex pheromone were tested via electroantennography on palps (electropalpography) of adult virgin females and on females in behavioural trials. We propose sulcatone (6-methyl-5-hepten-2-one) as a candidate substance for the female volatile pheromone and several long-chained alkanes and alcohols as candidates for contact pheromones. Apart from demonstrating that attraction of males to females depends on the latter’s developmental stage, our study suggests that pheromones can also play an important role between females, an aspect that requires further attention.

Highlights

Communication consists of a sender emitting information via a signal and a receiver who reacts by changing its behaviour or physiology (Wilson 1975)
We first tested whether females had a side preference by presenting double blank controls (Exp. 5, N = 20), we offered adult females a choice between an adult virgin female versus a subadult female to investigate if females can discriminate between the two developmental stages based on volatile cues (Exp. 6, N = 20)
Males significantly preferred the odour of adult virgin females to an empty control (17 vs. 3; binomial test, N = 20, p = 0.003, Fig. 1, Exp. 3)

Summary

Introduction

Communication consists of a sender emitting information via a signal and a receiver who reacts by changing its behaviour or physiology (Wilson 1975). Most studies on sex pheromones have been performed on insects (Symonds and Elgar 2008; Jacobson 2012) and there is ample information that females use pheromones to attract males (Ayasse et al 2001; Ando et al 2004; Harari and Steinitz 2013). Many sex pheromones have been identified in insects (Ayasse et al 2001; Francke and Schulz 2010), e.g. in numerous species of butterflies, in which females attract males over long distances with only. In turn, have developed highly sensitive antennal receptors to receive the female sex pheromone (Roitberg and Isman 1992). Some female insects have been shown to be capable of detecting female pheromones, suggesting that females can assess the presence of sexual rivals or even the density of signalling females in their habitat (Palanaswamy and Seabrook 1978; Harari et al 2011)

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