ORIGINAL RESEARCH article

Front. Insect Sci.

Sec. Pest Management

Evaluating the new product Norroa™ against Varroa destructor in managed honey bee (Apis mellifera) colonies

  • 1. University of Florida, Gainesville, United States

  • 2. Greenlight Biosciences Inc, Medford, United States

The final, formatted version of the article will be published soon.

Abstract

A novel RNA interference (RNAi) treatment (Norroa™ - active ingredient vadescana) was investigated for the control of Varroa destructor in honey bee colonies during periods of a nectar dearth and a nectar flow. In 2023, during a nectar dearth, and again in 2024 during a nectar flow, field trials were conducted to test the effectiveness of Norroa™ in limiting the growth of V. destructor infestations. In each season, 36 honey bee colonies were established for testing. During the nectar dearth, mite numbers started higher (4.56 mites/100 bees) and increased more in control colonies compared with the treated colonies, but differences were not significant. During the nectar-flow, Norroa™ maintained V. destructor populations at or below the initial infestation rate (2.31 mites/100 bees) for twelve weeks, compared with the control group that grew significantly higher than treated colonies. To understand the effects of Norroa™ better, a final trial was conducted uncapping honey bee pupae and examining mite reproduction. Mites from colonies that had been treated with Norroa™ were significantly less likely to lay an egg, or have any offspring emerge from the eggs laid. These trials demonstrate the promise of a new tool for beekeepers to control V. destructor.

Summary

Keywords

Apis mellifera, Honey bee, Norroa, RNAi, vadescana, Varroa destructor

Received

21 November 2025

Accepted

20 February 2026

Copyright

© 2026 Rawn, Prouty, Gautam, Jamison, Talton, Youngs, Narva, Manley and Jack. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Devan Rawn

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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