Male chemical cues as reliable indicators of infection in the wolf spider Schizocosa ocreata

Abstract

Sexual signals can convey important information about mate quality, such as critical information about a signaler's health status, helping an individual to avoid infected or immunocompromised conspecifics. Chemical signals are especially important in this context, because they represent an honest and dynamic signaling modality that receivers can use to make updated mate choice decisions to avoid compromising their own health. In this study, we investigated the viability of male chemical cues in the wolf spider Schizocosa ocreata as a reliable indicator of health status. Using video playback with images of an average male that is simultaneously paired with male cuticular compounds on filter paper, we show that females are more receptive to videos paired with cues from control males rather than infected males. We also show that these cuticular compounds can be isolated and retain similar female behavioral responses when extracted with a nonpolar solvent, suggesting that these cuticular compounds may not be just complex hydrocarbons, but a combination of cuticular compounds. This is the first evidence for female discrimination and recognition of male chemical cues in this species, which opens up important new avenues of research in a well‐studied species with complex multimodal signaling.

Female sex pheromone emission is affected by body condition, but not immune system function, in the orb‐web spider Argiope bruennichi

“…Here, immune challenge neither affected male pheromone signals, nor their attractiveness to females. In the only previous study investigating a correlation of chemical cues and immune function in spiders, on the other hand, video playbacks of a courting male wolf spider, Schizocosa ocreata , of average size and vigour were less attractive to females when presented together with filter paper containing chemical cues of males that were experimentally infected as compared with untreated males (Gilbert & Uetz, 2019). Likewise, recent studies on female pheromones in moths revealed contradicting results on relationships between immune system function and pheromone signals.…”

“…However, only few studies investigate a link between body condition and chemical traits in spiders. Gilbert and Uetz(2019) found that females of the wolf spider Schizocosa ocreata can discriminate between experimentally infected and control males based on cuticular cues. Moreover, an elegant study on the evolutionary background of male mate preferences in tow species of widow spiders (Johnson et al, 2011; MacLeod & Andrade, 2014), Baruffaldi and Andrade (2015) showed that males can discriminate fed from starved females by silk extracts alone.…”

Spiders, microbes and sex: Bacterial exposure on copulatory organs alters mating behaviour in funnel‐web spiders

“…Future physiological and microbiome research is needed to understand how the modification of bacterial communities in and on the body can alter behaviour. In S. ocreata , like in A. pennsylvanica , sexual partners also appear to be able to detect the presence of bacteria (pathogenic or otherwise) in their prospective sexual partners (Gilbert, Karp, & Uetz, ; Gilbert & Uetz, , ). We found no evidence that treatment with antibiotics altered courtship behaviour or survivorship, though future studies could ascertain whether antibiotic treatments reduced the presence of beneficial microbes that might play a role in spider mating.…”

Chemosensory discrimination of male age by female Psammodromus algirus lizards based on femoral secretions and feces

“…Besides, females might not show a high TF response to some chemical cues because this information would not be useful in the social context of our behavioral experiment. Thus, for example, in the wolf spider ( Schizocosa ocreat ), females did not show the ability to discriminate between male and female chemical signals and a blank control in a scent choice test, but another experiment suggests that females can use the chemical information in the context of males’ infection (Gilbert & Uetz, ). In a behavioral experiment with Podarcis muralis lizards, females did not choose between male morphs based on color or chemical cues, but they were more active when presented only to males’ scents (Sacchi et al, ).…”