Vol. 9, Special Issue 11, Part K (2025)

The study aimed to confirm the contact activity of essential oil from turmeric (Curcuma longa L.) against the red spider mite (Tetranychus truncatus Ehara) using leaf dip method at six concentrations (0.01, 0.02, 0.03, 0.05, 0.08 and 0.1%). The results of contact bioassay revealed that C. longa EO exhibited strong, dose-and time-dependent acaricidal effects against T. truncatus. Even at the lowest concentration of 0.01%, mortality reached 85.7% by 72 hours after treatment (HAT), while at concentrations of 0.03% and above achieved cent Percent mortality within the same period. At 0.05%, 100% mortality was recorded as early as 60 HAT, showing no significant difference from 0.03% at that time. At 72 HAT, the LC₅₀ and LC₉₀ values were 0.001% and 0.012% respectively. The safety evaluation of C. longa EO against the predatory mite Neoseiulus sp. showed that mortality reached only 9.52% (72 HAT) at 0.01%. Probit analysis confirmed that the LC₅₀ values of Neoseiulus sp. were significantly higher (0.054% at 72 HAT) when compared to that of T. truncatus, proving its environmental safety. Overall, C. longa demonstrated significant acaricidal activity on T. truncatus along with safety on the mite predator, Neoseiulus sp. indicating its high potential for managing T. truncatus populations.