Reported Acaricide Use and Varroa destructor Infestation in South Korean Apiaries: Findings from the 2025 National Active Surveillance Program

Varroa destructor is controlled mainly with acaricides, but resistance-associated mutations to fluvalinate and amitraz are widespread in Korean mite populations, and both compounds have been excluded from the national subsidy program (fluvalinate in 2023; amitraz in 2026). Using records from the 2025 national active surveillance program, we describe acaricide use reported by beekeepers for the months preceding three visits (post-overwintering, post-harvest and pre-overwintering), together with infestation measured at the same visits. After exclusion of records without usable treatment information, 83, 61 and 83 Apis mellifera apiaries were analyzed (227 apiary-round observations in total). Formic acid was the mainstay (75.4–84.3%). Fluvalinate remained in use after subsidy withdrawal (24.1%, 19.7% and 9.6%). Reported amitraz use was 56.6%, 31.1% and 47.0% at the three visits. Separately, 87.9% of apiaries (94/107) were Varroa-positive pre-overwintering by powdered-sugar roll (not comparable with the post-overwintering brood-inspection rate), and 30.1% of positive colonies had ≥10 mites/100 bees. Thymol was virtually absent (≤2.4%). Use of ≥3 chemical types within a recall interval was most frequent post-overwintering (42.2%; 54.2% when drone-brood removal was also counted). These single-year, self-reported data describe practice rather than treatment efficacy; they highlight the need to evaluate available treatment options and the factors influencing treatment choice.