Predation risk is one of the evolutionary forces shaping prey behaviours and life-history strategies across taxa. Predators often target vulnerable life stages of prey, but how prey females adjust their reproductive strategies in response to cues from injured conspecifics of these stages remains unclear. Using the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) and its prey, the spider mite Tetranychus ludeni Zacher (Acari: Tetranychidae), we first confirmed that P. persimilis significantly preferred T. ludeni eggs for feeding, indicating their higher vulnerability to predation compared to deutonymphs and adults. We then tested whether ovipositing T. ludeni females adjusted their reproductive performances and survival when exposed to olfactory cues from injured conspecific eggs, deutonymphs, or adults. Females responded most strongly to olfactory cues from injured eggs, reducing fecundity by 47.6–54.6% and producing smaller eggs, but without trading off longevity. Additionally, they altered offspring sex ratios, producing more dispersing daughters by fertilizing more smaller eggs when exposed to injured adult cues, an evolved strategy to escape from the risky environments. In contrast, egg hatching and immature survival were unaffected by conspecific cues. Our results demonstrate that T. ludeni females may discriminate among cues from injured conspecifics of different life stages, with the strongest vigilance elicited by cues from the most vulnerable stage (i.e., eggs). This study highlights the role of indirect, life stage-specific cues in shaping antipredator strategies, and suggests that non-consumptive effects of predation risk could influence prey population dynamics in ways beyond direct predation.