Bioactivity of Essential Oils from Patagonian Wild Plants: Acaricidal and Insecticidal Effects on and .

represents a major threat to honeybee colonies worldwide, prompting the search for alternative organic acaricides. This study evaluated the biological activity of essential oils extracted from three Patagonian wild plants-, , and -on both and . Chemical analysis revealed that oil was dominated by esquelenone (34.49%), by ascaridole (34.87%), and by -pinene (40.87%). All essential oils exhibited acaricidal activity, with showing the lowest LC against (1.1 µL/mL at 24 h). Toxicity assays on adult bees indicated that and significantly reduced bee survival, whereas did not appear to cause significant mortality (LC = 139.5 µL/mL). Repellency tests for and showed significant mite repellence. Larval assays revealed a high survival rate under treatment (survival rate > 80.24%), in contrast to the reduced viability observed with the other oils. The high selectivity index of underscores its potential as a selective and safe botanical acaricide. Moreover, its LC decreased over time, suggesting a residual acaricidal effect. These findings support as a promising candidate for sustainable control.