Oxalic Acid Varroa Control Gains NZ Registration

It’s been a long wait, but New Zealand’s beekeepers will very soon have available to them a fully-registered, long-acting oxalic acid varroa treatment, with UK-headquartered, global apiculture supplier Vita Bee Health recently gaining the necessary approvals.

For a decade or more oxalic acid ‘strips’ or ‘staples’ have been commonly used by New Zealand’s beekeepers to control varroa mite, but under an ‘own-use’ exemption provided by the Ministry for Primary Industries. Soon, though, beekeepers will benefit from a fully-registered, and thus proven, product with strong efficacy claims. VarroxSan is expected to hit the shelves of recently-relocated Auckland, and online, retailer Ceracell Beekeeping Supplies in October or November.

Made of food grade cardboard, impregnated with oxalic acid, VarroxSan trials have proven it to have an average efficacy rate of 96%, with treatments in the hive for six to eight weeks.

“It is long overdue,” says Ceracell export and marketing manager Thomas Clow.

“We have been wanting to have an alternative product available for quite a long time, over three years of waiting.”

Supply partner Vita Bee Health began the Agricultural Compounds and Veterinary Medicines (ACVM) registration process for VarroxSan in 2022. Hampered by Covid delays, final registration only took place on July 25 this year. The New Zealand approval for use follows successful applications in the country where VarroxSan is manufactured, Uruguay, in 2020, neighbouring Argentina in 2022, then the major market of the United States in 2024, before Costa Rica earlier this year.

“We are trying to bring it to beekeepers around the world because it is a product beekeepers are crying out for,” Vita Bee Health director Sebastian Owen explains.

“It provides a constant release rate over six to eight weeks. It provides all the benefits of oxalic acid and all the benefits of a strip treatment.”

Despite registration having been achieved in New Zealand, Kiwi beekeepers will have to wait at least a few months longer before VarroxSan hits the market. Popularity in the product from America has created manufacturing backlogs, and it will take time for the product to be shipped from Uruguay to New Zealand.

“It is selling faster than we can make it. The manufacturing facility is at full capacity, working 24 hours a day, six days a week, and still struggling to keep up with demand. It’s a nice problem to have,” Owen says.

VarroxSan is administered to hives in the form of four food-grade cardboard strips per full brood box of bees (one strip per 2.5 frames of bees) hung over frames. Each strip contains 18.42% of oxalic acid dihydrate. Trials across Uruguay, Argentina, Greece and the US show efficacy rates (percentage of mites killed) of between 92 and 98%, with an average of 96%.

Restrictions for use on the New Zealand label state the strips should be placed in hives for six to eight weeks and they should not be used when honey supers are present. Owen says this is a standard restriction across all markets, except the US, regarding oxalic acid products, but to their knowledge there is no residue in honey concern when using VarroxSan regardless of time of year.

Beekeepers in New Zealand have long been using ‘DIY’ oxalic acid impregnated materials during periods of honey collection.

While the final pricing for VarroxSan is yet to be calculated, beekeepers should not expect it to be priced nearly as low as the unregistered products. Vita Bee Health technical director Paulo Mielgo says there is a “huge difference” between home-use oxalic acid-based treatments and VarroxSan.

“You can buy oxalic acid in New Zealand for a cheap price, but this treatment is made at a factory using GMP – Good Manufacturing Practices (GMP) – so the costs are higher. We use active ingredient produced in a GMP facility. The cardboard we use is also stronger than that commonly used, so the bees will not chew it out as quickly. That allows treatment for six to eight weeks. It is also food grade, which means it is not one, not two, not three, but about 10 times more expensive than that same cardboard. Then, the impregnation process for this type of material must be longer and more controlled to ensure that each strip contains seven grams of oxalic acid. You put all that together, it is more expensive, but with a lot more technology and quality behind it, and it won’t give you any problems with your honey,” Mielgo says.

“At the end of the day, we are producing honey, so we need to be sure we are not putting anything which might contaminate honey into the hive.”

New Zealand has become the fifth country to approve VarroxSan for use in beehives, after a more-than-three-year application process undertaken by Vita Bee Health.

Owen adds that all those factors should be valued by beekeepers and Vita Bee Health are encouraged that, in the recently registered US market, they have been by a range of both small and large-scale beekeepers.

“When it states there is a certain amount of oxalic acid in the product, there is that amount,” Owen says.

“The strips are all the same height, weight and width and stable for the period it says they are stable for. The beekeeper can be really confident they know what they are getting, a safe, proven and effective treatment.”

Kiwi beekeepers can not quite get it yet, but both Vita Bee Health and Ceracell say the wait is nearly over. When it arrives, Owen says that, due to its organic nature and high level of efficacy, it will be able to fill a range of roles in beekeeper’s varroa control plans.

“We are not advocating replacing anyone else’s treatment. We see this as an additive thing. Beekeepers need as many options as possible, and we want them to use them all and keep cycling through them,” Owen says, adding “we are just adding another tool to the armoury which we think is a game-changing tool, because we all know it is desperately needed”.