Aspiring apiculturists at EIT Hawke's Bay's New Zealand Certificate in Apiculture (level 3) course are taught about treating their bees for Varroa. Photo / Paul Taylor
Aspiring apiculturists at EIT Hawke's Bay's New Zealand Certificate in Apiculture (level 3) course are taught about treating their bees for Varroa. Photo / Paul Taylor
Nearly one in 10 bee colonies in Hawke's Bay are dying due to increasingly deadly Varroa mites, according to a recent survey.
The Apiculture NZ 2021 Colony Loss Survey found the mid-North Island region reported 18.7 per cent winter loss rates and 8.6 per cent of all colonies in theregion lost to Varroa.
The mid-North Island region includes Hawke's Bay, Waikato, Bay of Plenty and Gisborne.
In comparison, 5.3 per cent of all living colonies were lost to Varroa nationwide in the 2021 winter season.
The survey also revealed that Varroa mites are now the leading cause of colony losses.
The leading reason for colony losses in the past six years of the survey was attributed to Queen problems, but Varroa is now responsible for nearly 40 per cent of losses nationwide.
Varroa mites are small parasites that live on honey bees and feed and reproduce on larvae which can spread viruses, cause malformation and shorten bees' lifespans, eventually destroying colonies.
Despite this, the survey found that a quarter of beekeepers don't monitor the success of their Varroa treatments - while four per cent of beekeepers don't treat for Varroa at all.
A close-up view of what a Varroa mite looks like. They live their entire life cycle inside beehives feeding off larvae and adult bees and spreading viruses. Photo / NZME
Chair of Apiculture New Zealand's Science and Research Focus Group Barry Foster said the Varroa mite has become even more devastating to bees than it was in the past.
"In 2000 it would have taken a lot more mites to kill a hive than it does now. We've probably got less resilient bees and the pathogens are getting more infectious, more virulent."
Foster said the issue was likely particularly bad in the mid-North Island and Hawke's Bay because of the amount of beehives in the area, and possibly over-stocking of hives in some instances.
"There is a lot of beehives in that area, a lot of pollination goes on in the Bay of Plenty, Hawke's Bay and Gisborne."
"If you have a lot of organisms in one area, pathogens will exploit that."
He said there is some complacency from beekeepers as shown by the survey data.
"If you really want to hang on to them and have them, then you've got to look after them, like any livestock."
Foster said education and awareness was a good start to addressing the issue.
"Beekeepers need to upskill themselves and actually do some monitoring and actually get those treatments in earlier."
His preference would be to see regional co-operation for Varroa treatments where apiculturists all treated at the same time.
"If you put your treatments in at the same time, the mite can't re-invade anyone else because everything is under treatment."
He recommended beekeepers joined Apiculture New Zealand to help spread information and improve communication around treatment.
EIT head of school for primary industries Nigel Udy said some of the survey data showing the number of beekeepers not treating for Varroa was very surprising.
"I tend to think if you do not treat for Varroa your hive will be dead most likely, if not within 12 months then within a couple of years."
Udy said he was also shocked that a quarter of beekeepers didn't monitor their hives.
"You need to be up to date with what's happening in your hives, you need to be up to date with Varroa numbers and infestation and what is working and what isn't working."
