The role of high-contrast male facial stripes in mitigating female aggression in the jumping spider, Plexippus paykulli

Vibrant male coloration and energetic courtship displays set jumping
spiders apart from most arachnids, which typically rely on non-visual
stimuli. Like many other spiders, female salticids engage in sexual
cannibalism, making courtship a risky but necessary endeavor for males. In
this study, we investigated the relationship between male coloration and
female aggression to better understand the interplay of attraction and
aversion during courtship. Many male jumping spiders sport conspicuous
coloration or high-contrast patterns that are reminiscent of the
coloration of many aposematic insects. The faces of Plexippus paykulli
males are adorned with bold vertical stripes they direct toward females
during courtship. We hypothesized that these stripes could function as a
sensory trap, leveraging female aversion to the signal to reduce the
likelihood of cannibalism. We tested whether spiders exhibit an aversion
to stripes in the context of predation by manipulating prey coloration and
testing spider preference for prey based on the presence or absence of
stripes. Then we conducted two courtship experiments by manipulating male
facial coloration to determine whether the presence of male stripes
affects female aggression and likelihood of mating. We also manipulated
female foraging drive in each courtship experiment (either diet or mating
status) to see whether common sources of natural variation among females
influenced response to courting males. We found that spiders showed an
aversion to stripes while foraging but that this aversion does not confer
reduced aggression from females toward striped males vs. males with
stripes obscured. However, stripes did affect the likelihood of male
reproductive success, as striped males mounted females more frequently
than non-striped males. Finally, female condition influenced female
response to courting males, with hungrier females showing higher
aggression and previously mated females being mounted less frequently than
non-mated females.