New Zealand beekeepers say the Varroa mite is the still most common reason for overwintering hive losses. The recently released New Zealand Colony Loss Survey shows the loss rate during winter 2022 was 13.5% identical to winter 2021. So while loss rates have levelled off, they have levelled off near the highest recorded rates since the survey began in 2015, and the rate of suspected varroa-related losses continues to increase.
Barry Foster of the Apiculture New Zealand Science Focus Group says the survey estimates that nearly half of all colony losses were lost to suspected varroa while losses attributed to queen problems, wasps and suspected starvation in 2022 were close to their long-term averages. In the survey beekeepers who lost colonies to varroa blamed ‘re-invasion’ with more than 38% of survey respondents saying that they treated for varroa more than once during autumn. Barry Foster says this is a timely reminder to beekeepers to “monitor, monitor and monitor their hives for mites.”