Pheromone communication among sexes of the garden cross spider Araneus diadematus

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.

Widow spiders alter web architecture and attractiveness in response to same-sex competition for prey and mates, and predation risk

“…While it is well established that animals gauge habitat suitability, in part, by the presence or absence of conspecifics 49 , it was not known that web-building spiders can sense the presence of female conspecifics via their sex pheromones and adjust their webs in relation to the perceived level of competition, and the threat of predation by natural enemies. Previously, sex pheromones of web-building female spiders were known in the context of sexual communication, attracting mates 50 , 51 , and expediting the sexual maturation of subadult males 52 , 53 .…”

“…1 ), and with these web-building spiders deemed not to have good vision 54 , 55 and not to produce sounds 55 , we predicted airborne chemicals (sex pheromones) to be the signals or cues revealing the presence of intra-sexual competitors. Spiders—including widow spiders—do produce sex pheromones, of which some have been identified 26 , 28 , 51 , 56 . Although female-produced sex pheromones primarily serve in sexual communication to attract males 28 , 57 , it was conceivable that female spiders can sense their species-specific pheromone (pheromone autodetection) and use this ability to gauge intra-sexual competition.…”

A road map of jumping spider behavior

“…It is possible that these sensilla also detect airborne chemical signals (akin to our sense of smell), yet how volatile chemical information is processed remains unclear (MÜller et al 2020). However, electrophysiological and behavioral experiments have shown that spiders are capable of detecting volatile chemical signals (e.g., Fischer et al 2021).…”

Non-targeted metabolomics aids in sex pheromone identification: a proof-of-concept study with the triangulate cobweb spider, Steatoda triangulosa

“…Spiders have received little attention in chemical ecology research 6 . There are some 50,000 spider species but only 15 sex pheromones have been identified to date 6 , 15 , 25 , possibly because spiders lack antennae as pheromone bio-detectors (see above), and the search for pheromone receptors has met with limited success 26 , 28 , 29 . To assess how non-untargeted metabolomics can aid in spider pheromone research, we selected the triangulate cobweb spider, Steatoda triangulosa , a synanthropic, cosmopolitan spider inhabiting buildings 30 , 31 .…”