For the past four years, researchers at Victoria University of Wellington have collaborated with GreenLight Biosciences to develop and test NorroaTM in New Zealand. Rose McGruddy and Phil Lester, of the university’s School of Biological Sciences, are part of a team that set up mini-hives to study how GreenLight Bio’s formulation worked to control varroa mites. This is a summary of their research.
Our journey has been exciting, involving extensive laboratory experiments and large-scale field trials, as well as productive, demonstrating that NorroaTM could virtually eliminate reproduction of the parasitic varroa mite.
In these experiments, small bee colonies were artificially infested with these tiny mites, which feed on fat stores, spread viruses, and are the leading cause of colony loss in New Zealand. Norroa prevented the mites from producing eggs, though the adult mites survived. Most important, the bees in our treated colonies remained healthy and unaffected.
These findings clearly show that NorroaTM has potential as a tool for mite control, providing a targeted and effective way to disrupt varroa reproduction without harming bees.
Our next step was to test NorroaTM in real-world conditions. Field trials confirmed its effectiveness in controlling mite populations, particularly in hives with low to moderate infestations. Colonies treated with NorroaTM saw a 75% reduction in mite densities compared to untreated colonies, with control lasting more than 18 weeks.
Notably, our trials showed that NorroaTM treatments significantly increased the winter survival rates of hives, which can help colonies endure tough conditions.
To further evaluate the impact of NorroaTM on bee health, we used tiny Radio Frequency Identifier (RFID) tags glued to the backs of bees, allowing us to track bee lifespans and foraging behavior.
Bees from NorroaTM-treated hives lived longer, made more frequent foraging trips, and completed their trips more efficiently than bees from untreated hives. These findings underscore the broader benefits of NorroaTM, highlighting its role in promoting healthier, more productive colonies.
Across New Zealand, the response from beekeepers has been overwhelmingly positive. They value NorroaTM’s targeted approach, which minimizes risks to bees and beneficial insects, as well as its ease of use. Many see it as a promising addition to their integrated pest management strategies.
Feedback ranges from “I would like to see this implemented as soon as possible” to “Whatever science can produce that maximises the health and longevity of bees, I will support.” The most telling comment–“When can I get some?”–reflects the excitement and demand for this new tool.
NorroaTM’s innovative mechanism, which halts mite offspring, combined with ease of application and beekeeper support, positions it as a practical solution for improving colony health and resilience.
We’re excited about NorroaTM’s potential to help beekeepers protect their hives and sustain New Zealand’s honey bee populations for the future.
To read more about Rose and Phil’s work, see their paper published in Pest Management Science.
