Varroa and Colony Losses: Practical Advice for Hobbyist Beekeepers

Varroa destructor is the leading cause of honey bee colony losses globally and is increasingly implicated in winter colony mortality in New Zealand. This study used data from the New Zealand Colony Loss Survey to evaluate the relationship between specific varroa management practices and over-winter colony losses among 5203 hobbyist beekeepers surveyed between 2023 and 2025. We find that beekeepers who did not treat for varroa experienced loss rates of 49.4% compared with 30.7% among beekeepers who treated. Conditional on treatment, colony losses declined as the diversity of products used increased and as treatment applications were spread throughout the year. For example, beekeepers using four or more products experienced losses of 21.2%, while those treating in three or more seasons of the year experienced losses of 24.8%. Multiple autumn treatments were also associated with lower loss rates. No statistically significant differences were observed among major treatment types when hobbyist beekeepers used a single treatment type in a single season of the year. While apiary size is negatively associated with loss rates, beekeeper experience is not. The results demonstrate that treating for varroa, product rotation, treatment throughout the year, and intensified autumn control are associated with substantially improved over-winter colony survival among hobbyist beekeepers.