Plasma-treated porous carriers for modulating clove essential oil release against Tropilaelaps mites in Apis mellifera colonies

Tropilaelaps mites are among the most destructive ectoparasites of Apis mellifera. The application of essential oil-based acaricides to control their populations is limited by rapid volatilization and short persistence under hive conditions. This study investigated pumice and ceramic balls treated with argon or helium non-thermal atmospheric pressure plasma (NTAPP), with or without water vapor, to modify the evaporation profile of clove essential oil for Tropilaelaps mite control. Plasma treatment did not significantly affect clove essential oil adsorption capacity (0.0072–0.0092 μL mg −1 and 0.0049–0.0065 μL mg −1 for pumice and ceramic balls, respectively). However, the He + H 2 O-treated ceramic ball exhibited significantly slower evaporation during days 2–8, although all treatments reached approximately 52–54% cumulative evaporation after 14 days. In laboratory bioassays using 5% clove essential oil, mite mortality differed between plasma-treated and untreated ceramic balls during the initial 30 min of exposure for the 0 and 24 h evaporation periods. However, both treatments resulted in 100% mite mortality after 3 h of exposure across all evaporation periods (0, 6, and 24 h). Adult bee survival was comparable between the two treatments but differed from the control. During the 28-day field trial, colonies treated with 5% clove essential oil-loaded ceramic balls showed numerically lower mite infestation than those treated with formic acid, with comparable adult bee populations and no significant differences among treatments. Overall, plasma surface modification modulated the evaporation profile of clove essential oil without compromising its acaricidal activity, supporting the potential use of plasma-treated porous carriers as delivery systems for Tropilaelaps mite management.