Formic Acid Gel Protects Bees and People

Beekeepers could soon have an alternative way to save their hives from varroa mites, pests that are becoming resistant to the standard control, fluvalinate, sold as Apistan. A new treatment--a gel containing formic acid--has been licensed to industry by the USDA's Agricultural Research Service.

Apistan-resistant mites have been found in parts of the United States. ARS scientists at the Bee Research Laboratory in Beltsville, Md., developed the formic acid gel and have applied for a patent. In field tests, the formic acid gel killed up to 84 percent of varroa mites and 100 percent of tracheal mites, another bee pest.

ARS issued a license Monday to Betterbee, Inc., of Greenwich, N.Y. The company must obtain approval from the Environmental Protection Agency once they develop a product. The formic acid gel could be available to beekeepers next spring.

The gel formulation can ease the path to EPA registration because it reduces the risk of exposure to formic acid compared with the formic acid spray used in Europe. The spray is effective, but the highly toxic acid evaporates quickly. This puts bees and beekeepers at risk if spraying is done incorrectly. Also, spraying must be repeated, unlike the gel.

The new treatment is composed of formic acid mixed with a food-grade gelling agent and sealed in a small plastic bag. Beekeepers would simply slice open the bag and leave it in the hive. After the acid evaporates, it leaves a harmless residue that won't contaminate the hive or the honey.

Varroa mites cause economic losses not only to beekeepers but also to farmers who depend on honey bees to pollinate $10 billion worth of U.S. crops. In California, for example, half a million bee colonies are needed each year to pollinate the almond crop.

Scientific contact: Hachiro Shimanuki, ARS Bee Research Laboratory, Beltsville, Md., phone (301) 504-8975, fax (301) 504-8736, hshimanu@asrr.arsusda.gov.