Apiculture NZ reminds beekeepers to monitor for varroa destructor mite

Beekeepers believe the varroa destructor mite is the most common reason for hive losses over the winter. File photo / Warren Buckland

A tiny mite is continuing to be the bane of beekeepers’ existence.

An industry survey of colony losses shows beekeepers believe the varroa destructor mite to be the most common reason for hive losses over the winter.

Last winter, the overall loss was 13.5 per cent with casualties almost identical to the previous winter.

While loss rates have levelled off, they’re still near the highest recorded rates since the survey began in 2015, and suspected varroa-related losses continue to rise.

The survey estimates that 6.4 per cent of all living colonies were lost nationally to varroa and related complications last winter - up 20 per cent on the 2021 winter.

Varroa accounts for nearly half of all colony losses.

In contrast, losses from queen problems, wasps and suspected starvation last winter were close to their long-term averages.

Varroa management is on the rise with only 1.5 per cent of surveyed beekeepers failing to treat hives in the 2021-22 season. Every beekeeper with more than 50 colonies was treated for varroa last year.

Beekeepers who lost colonies to varroa were asked what they thought went wrong.

The most common reply was the belief that varroa had re-invaded hives. More than 38 per cent of those surveyed treated for varroa more than once during autumn.

Apiculture New Zealand science focus group chairman Barry Foster said this was a timely reminder for beekeepers to “monitor, monitor and monitor” their hives for mites.