Plants integrate chemical signals to activate (or prime) defenses against herbivores and pathogens. Previous studies suggest that this induction does not always require direct herbivore feeding, indicating the involvement of alternative elicitors such as chemical cues. In this context, the citrus– Tetranychus urticae system represents an ideal model, as it includes genotypes with contrasting responses to infestation: Citrus aurantium (“sour orange”) displays a resistant phenotype, whereas Citrus reshni (‘Cleopatra’) is highly susceptible. While it is known that herbivore infestation alters plant volatile profiles, generating genotype-dependent volatile organic compound (VOC) blends, it remains unclear whether volatiles emitted directly by the herbivore, without plant contact or feeding damage, are sufficient to modulate host plant defenses. The aim of this study is therefore to determine whether citrus plants can perceive volatile cues emitted by T. urticae and whether these signals influence host immune responses. Citrus genotypes with distinct susceptibility to T. urticae were exposed to volatile cues emitted by spider mites in the absence of physical contact or feeding damage. Plant defensive responses were evaluated by analyzing changes in defense-related signaling and metabolic profiles associated with induced resistance. Comparisons between susceptible and resistant genotypes allowed the assessment of genotype-dependent responses to mite-derived olfactory cues. Preliminary results indicate that citrus plants can detect volatiles emitted by spider mites and trigger specific defense responses. In the susceptible genotype (C. reshni), these volatile cues appear to suppress immune responses, whereas resistant genotypes (C. aurantium) remain unaffected or even show signs of defense activation, potentially priming the plant for future infestation. These findings suggest that volatiles released by T. urticae may function as a novel mechanism of defensive manipulation of the host prior to herbivory, allowing the herbivore to influence host immunity before feeding begins. This highlights the role of herbivore-derived olfactory signals as previously overlooked modulators of plant signaling pathways and host defense dynamics. Our results provide new insights into how herbivore-emitted volatiles interact with plant signaling networks to shape host immunity. Understanding these mechanisms may reveal key components involved in defense modulation and clarify how herbivore-derived cues manipulate plant responses in a species-dependent manner. Ultimately, this knowledge could contribute to the development of more sustainable plant protection strategies by exploiting chemical signaling involved in plant–herbivore interactions.