The parasitic mite Varroa destructor first arrived in New Zealand twenty years ago. Since then, local honeybees have been unable to survive without the assistance of humanity, because the parasite threat has been so intense.
Until now, bee colony losses were thought to be due to queen bee problems. This year, according to the annual surveillance report from the Ministry for Primary Industries, more bee colonies are now lost due to the varroa mites than for any other reason. This is a first in the history of the survey.
Instead of spraying miticides on bees, an effective treatment for combating varroa is to position plastic strips inside the hives. This way, the strips are effective as bees walk around the hive on the strips, and the material is absorbed into their bodies where it kills the mites. According to Mark Ross, chief executive of Agcarm, it is important to get both the dose and the timing of the treatment right.
This unrelated 4:05-minute video by NSW DPI Agriculture shows some extreme infestations of varroa mites in New Zealand bee colonies:
Such a step is necessary to protect bees from these bee killing mites. According to Ross, varroa has already spread across the country and has wiped out wild bee colonies. He recommends that beekeepers be vigilant and actively check for the presence of mites. If they are found, the hive should be treated with miticides right away and in the right way.
If in doubt about what the right dose, timing, or way is, beekeepers are advised to follow the manufacturer’s instructions.
The Ministry for Primary Industries commissioned Manaaki Whenua-Landcare Research and tasked them to conduct a colony loss survey annually since 2015, so losses over time can be monitored and bee health can be improved.
Nearly half of New Zealand’s beekeepers participated in the 2021 winter survey. It was found that there was an overall loss rate of 13.6 percent. Around 109,800 colonies were represented, and this indicates that 2.3 percent more bees were lost in 2021 than in 2020.
Varroa destructor parasitic mites have devastated bee colonies around the world for many years, causing colony collapse disorder (CCD) and so far, there has been no real solution for this disaster.