FORMIC ACID GEL-STRIP The application of formic acid to honey bee colonies for the control of tracheal mites and varroa mites has been shown to be generally effective and has been registered for use against these pests in several European countries. However, the application of liquid formic acid has several draw backs i.e. obtaining correct dosages, potential hazards to the applicator and multiple applications are required. Medivet Pharmaceuticals of High River Alberta is developing a formic acid gel-strip to overcome these problems. Willy Baumgartner of Medivet feels that the potential for a one shot application is feasible. However, additional work is required to obtain a formulation which will give the necessary control. Medivet has had the cooperation of Dr. Don Nelson of the Beaverlodge Research Station, Kerry Clark and Paul Van Westendorp of the B.C. Ministry of Agriculture, John Gruszka from Saskatchewan Agriculture, and Dr. Bill Wilson from USDA in evaluating initial formulations. The gel-strip is being developed to accomplish several objectives at the same time; to provide a method that requires only one application, to make the method of application easy and safe for the applicator, and to provide more uniform evaporation over the treatment period. How does the gel-strip work? The gel formulation has formic acid incorporated into it. The gel is encased in a plastic tube about 12 inches long and 2 inches wide with holes on one side, which are covered by a sticky over-wrap. The gel-strips look very much like the flavoured ice-cicles that your kids buy. The gel-strip is stable, until the over-wrap is removed, which exposes the formic acid gel to the environment. Thus, application is easy: remove the over-wrap, place across the top bars of a bee colony (holes downward) and replace the colony cover. The evaporation of the formic acid takes place over a three week period and with one treatment the colony receives the required amount of formic acid. Work is continuing to determine the proper evaporation rate, which will deliver the required formic acid dosage over the treatment period. Formic acid has been approved for use in Canada. The formic acid gel-strip has given about 70% control of tracheal mites. A new formulation is being evaluated this spring. Hopefully the level of control can be increase to the same level as three weekly applications of 65% liquid. ------------------------------------ contact D.L. Nelson for further information Agriculture and Agri-Food Canada Box 29, Beaverlodge, Alberta T0H 0C0