Antipredation escape behaviour differs between fighter and sneaker males in the two-spotted spider mite.

Predation risk can strongly influence the evolution of reproductive tactics because behaviours that enhance mating success often increase vulnerability to predators. Males of the two-spotted spider mite, Tetranychus urticae, exhibit distinct reproductive tactics, including fighting and sneaking, as a conditional strategy. We investigated whether escape behaviour in response to predation risk differs between fighter and sneaker males during precopulatory mate guarding. To examine responses to different predator-associated cues, we introduced different developmental stages (adult female, deutonymph, protonymph, and larva) of the predatory mite Phytoseiulus persimilis to guarding males and quantified escape timing. Sneaker males showed significantly delayed escape responses compared with fighter males. Female survival during predator encounters varied depending on both male tactic and predator developmental stage. Although escape responses appeared to vary among predator developmental stages, the interaction between male tactic and predator stage was not statistically significant. We also observed counterattacking behaviour directed toward predators in male T. urticae. Most counterattacks were performed by fighter males, indicating a potential behavioural association between predator-directed aggression and male reproductive tactics. Our findings demonstrate that reproductive tactics are associated with differences in antipredator responses and provide new insight into behavioural evolution under the trade-off between reproduction and predator avoidance.