Complex courtship displays facilitate male reproductive success and plasticity in signaling across variable environments

Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, to maintain effective communication. Male Rabidosa rabida wolf spiders produce complex courtship signals, consisting of both visual and seismic components. We test the hypothesis that the complex signaling of R. rabida contributes to male reproductive success in variable signaling environments. We first examine the condition-dependence of foreleg ornamentation (a presumed visual signal) and seismic signal components and find that both may provide potentially redundant information on foraging history. Next, we assessed reproductive success across manipulated signaling environments that varied in the effectiveness of visual and/or seismic signal transmission. In environments where only one signal could be successfully transmitted (e.g., visual or seismic), pairs were still able to successfully copulate. Additionally, we found that males altered their courtship display depending on the current signaling environment. Specifically, males reduced their use of a visual display component in signaling environments where visual signal transmission was ablated. Incorporating signals in multiple modalities not only enables R. rabida males to maintain copulation success across variable signaling environments, but it also enables males to adjust their composite courtship display to current signaling conditions.

Predator-naïve fall field crickets respond to the chemical cues of wolf spiders

Few studies have addressed whether terrestrial insects assess predation risk via chemical cues. We exposed predator-naïve fall field crickets ( Gryllus pennsylvanicus Burmeister, 1838) to filter paper containing the chemical cues of three wolf spiders ( Hogna helluo (Walckenaer, 1837), Rabidosa rabida (Walckenaer, 1837), Rabidosa punctulata (Hentz, 1844)), the house cricket ( Acheta domesticus L., 1758,) and blank filter paper. Crickets exhibited greater immobility and reduced speed of movement when exposed to chemical cues of all three spider species. Crickets exhibited reduced speed with increasing mass of R. punctulata, suggesting that larger spiders may pose a greater risk. Cricket response did not differ between cues of H. helluo fed conspecific crickets versus H. helluo fed house crickets, suggesting that crickets cannot distinguish between cues from H. helluo fed phylogenetically similar crickets. Our work nevertheless demonstrates that naïve field crickets respond to chemical cues of several species of wolf spiders.