HopGuard II, potassium salts of Hops Beta Acids (K-HBAs), is produced from the cones of female hop plants. This biochemical miticide has been shown to be effective in combating varroa mites in bee colonies. It is manufactured by BetaTec Hop Products, a wholly owned subsidiary of Barth- Haas Group, Inc. of Yakima, Washington.

Registration status for HopGuard II has recently changed from Emergency Section 18 registration (which each state pesticide regulatory agency must apply for a state registration, as OR did) to Environmental Protection Agency (EPA) registration Section 3 nationwide. The various states (including OR), must still approve a State label which the Oregon Department of Agriculture has done. .

HopGuard II a contact pesticide, whereas the other organic acids used to combat varroa mites  (Oxalic, approved just last year by EPA, and Formic (MAQS) are effective as vapors. Hops contain two prominent organic acids, alpha acids—known to brewers as “flavor” hops—and beta acids, known as “aroma” hops. It is the beta acids that have been found to have anti-Varroa activity. Tthe Pacific Northwest states of Oregon, Washington and Idaho’s panhandle grow 97.8 percent of the hops in the United States. Most hop farms are family-owned and independently run operations

The new formulation is 16% beta acids painted on cardboard strips. They are to be used in the brood boxes. Two strips per brood box can be used up to three times per year. Since the product contains only “Generally Recognized as Safe” (GRAS) ingredients (product based on naturally-occurring materials), the manufacturer believes the product can be used in the hives anytime—even during a honey flow.

Have your tried HopGuard II? Organic acids (and high concentrations of essential oils) are considered safer to both bees and the planet. For mite killing effectiveness, hives need to be “hot fumigation chambers” for best results when using most oils or acids. Temperature or fumigation conditions however does not seem to be an issue with HopGuard II.

Many beekeepers who initially tried HopGuard didn’t like it. It was messy and stinky and stained everything. The manufacturer has greatly improved the cardboard strip delivery of HopGuard II. If you tried it and didn’t like it, you might check out the new, improved product delivery. It will work best when little or no brood is in the colony It can be used when honey supers are in place but may not be as effective in reducing high mite populations for large colonies with brood.

More data and beekeeper experiences are needed to fully define how HopGuard II should be used for maximum effectiveness in an IPM approach to mite suppression.  See information on HopGuard II in the Tools for HBHC Varroa Management  http://honeybeehealthcoalition.org/varroa/ and for more  information on Beta Tec see www.betatechopproducts.com