Varroa Increasingly Responsible
New Zealand beekeepers have reported varroa to be the most common reason for over-wintering hive losses for the first time, according to the recently released NZ Colony Loss Survey.
The 2021 Survey found varroa was responsible for nearly 40% of all losses. This marks a change in the primary cause, with queen problems having consistently been attributed as the key reason for colony losses in the past six years of the survey.
The Survey noted that an estimated 5.3% of all living colonies were lost to varroa and related complications over the 2021 winter, significantly higher than the 1.6% recorded just five years ago.
Beekeepers surveyed reported a number of reasons for the losses due to varroa; including reinvasion post treatment and timing issues with treatments. Nineteen percent believed their varroa losses were due to ineffective products.
The report makes for sobering reading says Barry Foster, chair of Apiculture New Zealand’s Science and Research Focus Group.
“While there are multitude of factors attributed to varroa losses it is worrying that approximately 4% of beekeepers surveyed did not treat for varroa at all during the 2020/2021 season and that about a quarter of beekeepers surveyed do not monitor the success of their treatments, says Barry.
“Treating is only the first part of varroa management; you have to monitor to make sure those treatments have worked—otherwise you are leaving your hives, and the hives of others, at real risk.”
“The fact that our colony losses are increasing year on year is a worrying trend and we need to up the ante in how we address the issues. That requires a united commitment to investment in research and education and a good start would be a commodity levy, something currently missing in the bee sector,” says Barry.
For the second year, NZ Colony Loss Survey asked for beekeepers’ sentiment on range of factors. Respondents were less positive about the economics of beekeeping, environmental factors, and the beekeeping lifestyle than in 2020. The report notes that “Given challenges presented by COVID-19, and low prices for non-mānuka honey, coupled with a sharp increase in reported varroa and wasps, a more pessimistic outlook is perhaps not surprising.”
Biosecurity New Zealand’s Annual Survey Supports Aotearoa’s Beekeepers
The Winter Colony Loss survey results are out now and show that the country’s beekeepers are serious about working together to support a strong bee industry.
Biosecurity New Zealand senior scientist Richard Hall says more beekeepers than ever took part in this survey, the seventh so far.
“This level of involvement and our beekeeper’s transparency in self-reporting shows how seriously they take biosecurity, and how valuable Biosecurity New Zealand’s support is in strengthening the bee industry.
“Strong biosecurity systems and management of pests and diseases are essential to production and the data gathered this year will help beekeepers identify where they need to focus their management efforts,” says Dr Hall.
This year’s survey showed that some 13.6% of beehives were lost over winter 2021. The increase of 2.3 percent on 2020’s results is closely attributed to a growth in varroa mite and related complications.
“While these numbers are worth exploring, we’re still seeing New Zealand’s winter colony loss rates are far less than our counterparts are finding in countries like the USA and Canada. Varroa mite is a pest that can be managed and we’re looking at new ways to support industry in dealing with the ongoing challenge of varroa.”
In responding to the survey, most beekeepers reported that their current varroa treatments are effective, but that they lose colonies if they get the timing of the treatment wrong, under-dose or that they pick up varroa from reinvasion from other colonies. This year’s survey also found not all beekeepers had treated for varroa.
“We’re reinforcing that beekeepers need to apply treatments available to keep the mite under control, follow manufacturer’s instructions, and frequently monitor mite levels so quick intervention can be made”.
“It’s the right season now to be alert to the needs of their bees and make a plan to combat varroa ahead of time. From what beekeepers are telling us—timing of treatment and monitoring for reinvasion is crucial”.
Dr Hall says that as well as the education campaign, Biosecurity New Zealand has funded a new research project to better understand how varroa treatments are used in New Zealand and where gaps in knowledge may be. This research will begin later this year.
“2021 saw more beekeepers registered than in New Zealand’s history. With this kind of growth, particularly in smaller operations and hobbyists, our support is essential to ensure this primary industry is equipped with the best information. This two-pronged work will help them know what biosecurity risks to look out for and how to manage them.”
The Winter Colony Loss survey is conducted by Manaaki Whenua Landcare New Zealand to provide Biosecurity New Zealand with data to ensure support is directed where it’s most useful for the bee industry.
More information on the latest Winter Colony Loss survey and the full report can be found on the Biosecurity New Zealand website.
Downloadthe Bee Biosecurity Visual ID Guide, and the varroa mite factsheet at: mpi.govt.nz/bee-pests-and-diseases
