Food-grade mineral oil and thymol fog application as a natural alternative to treating honeybee mites

2009 Annual Report for FNE08-641

Project Type: Farmer
Funds awarded in 2008: $7,556.00
Projected End Date: 12/31/2011
Grant Recipient: Bee-mus Honey
Region: Northeast
State: New York
Project Leader:
Heather Kyser
Bee-mus Honey

Food-grade mineral oil and thymol fog application as a natural alternative to treating honeybee mites


2009 Interim Report

Project Goals

Honey bee colonies are diminishing because of developing resistance of Varroa mites to chemicals and pesticides, thus stressing the importance and need of a natural and sustainable mite control method. Being conducted by Bee-mus Honey, this SARE project is investigating the use of food grade mineral oil (FGMO) and thymol (a natural plant extract) in the form of a fog as a natural and economic alternative to pesticide use for the control of Varroa mites within honey bee colonies. The primary goal of this project is to test the effectiveness and sustainability of FGMO/thymol fog as a mite control method and prove that it is a safe, extremely cost-effective, and an environmentally friendly acaricide for honey bees.

Updated Information

At the beginning of the SARE research project in the spring of 2008, Bee-mus Honey started with fifteen research hives – ten experimental and five used as control. All fifteen bee hives are within the same yard with approximately ten meters distance between the control and research hives (to eliminate potential drifting of the fogging materials from the experimental hives to the control hives). One control hive was lost in July, most likely due to queen failures, even though several queens were introduced. Therefore, a total of fourteen hives – four control and ten experimental – entered into the 2008-2009 winter season.


Due to a job change, I have been without a cooperator since the beginning of the grant. But on a more positive note, I have received endless valuable assistance and mentoring from a longtime beekeeper and pioneer in the area of fogging with food grade mineral oil. I am in contact via e-mail with this gentleman almost daily, and he provides me with insight and suggestions that I gratefully appreciate.

Methods of the Project

In the spring of 2008, Bee-mus Honey began research on the efficacy and specific application techniques of FGMO/thymol fog with the use of a Burgess Propane Fogger to determine its value as a preventative control for tracheal and Varroa mites. Research was conducted on fifteen bee hives – ten randomly selected experimental hives and the remaining five untreated controls. Fifteen packages of Russian bees (three pounds each) were purchased and installed on April 22, 2008. The bees were placed on new foundation to minimize variability and to rule out possible residues in old combs. All packages were fed granulated sugar to supplement feeding.

All hives were installed with screened bottom boards to allow for mites to drop away from the hives (and not re-enter) when fog treatment is not occurring. All hives had sticky boards installed (beneath the screened bottom board) immediately before fog treatment and left in place for 24 hours.

Beginning May 3rd, FGMO/thymol was fogged weekly into the entrance of the research hives. The fog provides the bees with a film of FGMO/thymol creating a slick surface to which the mites cannot cling. No fogging was performed on the control hives. Varroa mite drops (for all 15 hives) were collected, counted and recorded 24 hours after each fogging treatment to distinguish mite drop due to treatment from natural mite drops. Research was completed for the season on October 5th, 2008.

FGMO/thymol fogging will resume once again in the spring of 2009, and continue through 2010 to obtain sufficient data through replication. Because of the anticipation of some 2008/2009 winter colony losses, package bees will be purchased in the early spring to maintain a total of fifteen hives. Exact methods and formula for FGMO/thymol as used in 2008 will be used in 2009 and 2010. No changes or alterations to the research will be made at this time.


As this interim report is being written, it is thought to be too early in the research project to quantify the success of the use of FGMO/thymol as a Varroa mite control on honey bees. But, as of October 2008, qualitative results appeared to be extremely supportive of the effectiveness of fogging with FGMO/thymol for the control of Varroa mites.

Overall, the ten experimental hives entered the winter weighing more than the control hives, suggesting that the fogging successfully controlled the mite infestation within the experimental hives making them stronger and healthier. On the contrary, the four control hives (one control hive was dead in July) did not weigh as much, indicating less honey stored for the winter months. Furthermore, the experimental hives produced a much larger amount of fall honey (per hive) than the control hives, further supporting the hypothesis that fogging will produce stronger honey-producing hives. Findings indicate a positive direction of this research project for the next year.

Site Conditions Affecting the Results

The package bees did not arrive until the end of April, thereby limiting the amount of time the bees had throughout the nectar and pollen flows to build up their winter storage of food. Furthermore, the honey bees were under stress from being shipped, slowing the start of the research project. Being that all packages were installed in new hives with new foundation, the bees had to work hard at building up comb before any honey and pollen could even be stored. Our area (western New York) experienced a freeze early and snow fall in May, resulting in lack of Locust flow, thereby further delaying the nectar and pollen collected by the honey bees from this important source tree, Also, some of the packages did not accept their queen, resulting in new queens being purchased and introduced. As a result, some of the hives were slow to begin building up comb. The late start may have affected the strength and food storage of the hives entering the winter.

The majority of the hives entered the fall appearing to be strong and healthy. But once again, cold and wet weather came upon us – much earlier than anticipated. As I write this report on December10th, we have received over four feet of snow with daytime temperatures occasionally not getting out of the teens. This may be another factor to consider when looking at winter survival in the spring.

In spite of the above-mentioned conditions that may have negatively affected the research results, I have great expectations for the project next year since I will have an entire season to work.

Economic Findings

The research project has not had a major impact on our farm income this year, but I do anticipate a much greater surplus honey crop next year. The honey bees spent most of this past season building up enough comb for storage of honey and pollen, with not much surplus. But now that the comb is drawn, I would expect a much larger surplus of honey – especially from the experimental hives. Nonetheless, during the 2008 season, the experimental hives (ten) produced 312 pounds of surplus honey and the control hives (four) 60 pounds. Comparing results, the hives treated with FGMO/thymol produced twice as much honey as the control hives.

New Ideas

At this time, there will be no change in the research being performed. The exact methods used for the season of 2008 will be used for the 2009 and 2010 seasons. It is too early to quantify the success of the research. As stated above, next year may disclose much more.

Once this project is complete (2010), the next step will be to inform other beekeepers about the success of fogging as an effective, economic, and simple mite control method for honey bees. Already, there have been members of the Chautauqua County Beekeepers Association who have observed (and participated!) in the actual fogging process. They are amazed at the simplicity of the treatment. I am highly optimistic about the success of using FGMO/thymol fog as a control of Varroa mites on the honey bees. It will be exciting to perform the research during 2009!

Rodriguez, P.P. 2004. Food Grade Mineral Oil (FGMO) for Mite Control: 11th Anniversary. American Bee Journal. December 2004.

Rodriguez, P.P. 2004. FGMO-Thymol Application Improved For Varroa Mite Control. American Bee Journal. March 2004.

Rodriguez, P.P. 2003. Analysis of Honey for Traces of Thymol. Laboratorios Apinevada, Granada Spain. December 2003.

Rodriguez, P.P. and Harris, C.E. 2003. Food Grade Mineral Oil -Thymol Widen Alternatives for Honey Bee Mite Control. American Bee Journal. September 2003.

Rodriguez, P.P. 2003. Food Grade Mineral Oil (FGMO) as an Alternative Treatment for Honey Bee Mites. American Bee Journal. January 2003.

Rodriguez, P.P. 2002. Analysis of Honey from Hive Having 3 Years Use of FGMO. Laboratorios Apinevada, Granada Spain. July 2002.

Rodriguez, P.P., Campbell, M. and Campbell, L. 1999. Mineral Oil as an Alternative Treatment for Honey Bee Mites, Part 2 – Methods of Application and Test Results. December 1999. PDF Format.

Rodriguez, P.P. 1999. Mineral Oil as an Alternative Treatment for Honey Bee Mites – Methods of Application and Test Results. May 1999. PDF Format.

Rodriguez, P.P. 1997. Dr. Pedro Rodriguez’s 2nd release regarding his mineral oil research entitled “Mineral Oil for bee mites Treatment: Phase II”. August 26, 1997. PDF Format.

Rodriguez, P.P. 1997. Dr. Pedro Rodriguez’s release regarding his mineral oil research entitled “Bee Mites And Mineral Oil”. Posted to BEE-L. July 12, 1997. PDF Format.



David Munsee

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Techincal Advisor
3542 Turner Rd.
Jamestown, NY 14701
Office Phone: 7166649502