This study aimed to evaluate the efficacy of various control alternatives against Varroa destructor in Apis mellifera colonies in a semi-arid region of Mexico. One hundred and ten homogeneous colonies, with a uniform population and infestation level of V. destructor, were randomly distributed into the following 11 experimental groups (10 colonies/group): amitraz, oxalic acid in glycerin (OA-G), oxalic acid in sugar syrup (OA-SS), ethanolic extracts of Bursera penicillata, Larrea tridentata, and Lippia graveolens, powdered sugar dusting, three vehicle controls (vegetable oil, ethanol, glycerin), and one untreated control. Efficacy was determined by recording mite fall during the treatment period relative to a subsequent reference treatment. Significant differences were observed among treatments (p < 0.0001). Amitraz was the most effective (94.4%), followed by OA-G (85.1%). The OA-SS and plant extracts showed intermediate efficacy (62.1% to 73.7%), while sugar dusting showed lower values (55.8%) but still higher than the control (31.2%). These findings support the restricting of amitraz use to minimize resistance risk and suggest implementing OA-G as a high-efficacy alternative. Furthermore, ethanolic plant extracts and powdered sugar dusting combined with sticky bottom boards may serve as accessible, complementary tools within integrated pest management programs to reduce reliance on synthetic acaricides and mitigate the development of resistance.
Medrano et al. (Fri,) studied this question.