Title: Evaluation of Food Grade Mineral Oil Treatment for Varroa Control
Submitted to: American Bee Journal
Publication Type: Popular Publication
Publication Acceptance Date: May 25, 2004
Publication Date: November 1, 2004
Citation: Elzen, P.J., Cox, R.L. 2004. Evaluation of food grade mineral oil treatment for varroa control. American Bee Journal. 144(12):921-923.
Interpretive Summary: The Varroa mite (Varroa destructor) is the most serious pest attacking honey bees in the United States. Without control measures applied, an entire apiary can collapse in as little as two years. Currently there are four miticides approved by the United States EPA for national or specific state use against Varroa: Apistan® (fluvalinate), CheckMite+® (coumaphos), Sucrocide® (sucrose octanoate esters) and Api Life Var® (a blend of thymol, menthol, eucalyptus, and camphor).
Both Apistan and CheckMite have given excellent control in the past, but now Varroa has developed resistance to these compounds in many parts of the United States. Therefore, new Varroa control methods are very much in need at the present time. The goals in developing new compounds for Varroa control are that the product be effective, produce minimal effects on colony and queen viability, have little concerns for human safety (both in application and in residues), and be easy to apply and economical to treat.
Beekeeper testimonials from various countries indicate that food grade mineral oil (FGMO) provides effective control of Varroa. Food grade mineral oil applied with an insect fogger was evaluated for Varroa mite control in honey bee colonies by comparison to an industry standard, coumaphos strips, and an untreated control group (eight colonies per treatment group). During the six-week test period, the Varroa populations increased in untreated colonies and those treated with FGMO, while those treated with coumaphos strips decreased greatly.
Coumaphos-treated colonies averaged 96.1 to 99.4% fewer Varroa than the untreated colonies. These data indicate that under South Texas spring conditions, FGMO fogging of hives is of no benefit in controlling Varroa mite populations or improving the overall health of the colony during a 6-week test period.
In contrast, coumaphos worked very well to control mite populations, allowed colonies to grow in population size and increase honey stores. Efficacy was measured in several ways, all indicating greater than 90% control of Varroa compared to the untreated colonies. These results agree with a previous report that FGMO is largely ineffective in Varroa control. In addition to providing no control for Varroa, FGMO applied in an insect fogger may pose a fire and/or health hazard to beekeepers and bees.
The health hazard of exposure to FGMO through inhalation and exposed skin is unknown. Possible contamination of honey and other beehive products with FGMO or any byproducts of heating the oil is also cause for concern. Some beekeepers and bee researchers have suggested using the FGMO as a carrier to apply other miticides to the colony. Exposure to a "hard chemical" such as an organophosphate insecticide in oil during this fogging application method through inhalation or the skin may pose significant human health threat to the beekeeper. This practice should be strongly discouraged.
Technical Abstract: Food grade mineral oil (FGMO) applied with an insect fogger was evaluated for varroa mite control in honey bee colonies by comparison to an industry standard, coumaphos strips, and an untreated control group (eight colonies per treatment group). During the six-week test period, the Varroa populations increased in untreated colonies and those treated with FGMO, while those treated with coumaphos strips decreased greatly and, consequently, averaged 96.1 to 99.4% fewer Varroa than the untreated colonies at the end of the test period, by the alcohol wash and sticky board methods, respectively. In addition to providing no control for Varroa, FGMO applied in an insect fogger may pose a fire and/or health hazard to beekeepers and bees.