Adding iron to the bees’ diet helps to prevent winter mortality. This is the result of field trials with beekeepers. The trials were conducted in the Netherlands in 2011 and 2012, and in Belgium, France and the USA in 2012. The iron was mixed with a sugar solution and administered to the bees at various times between mid-July and mid-November. The best results were attained when the iron was administered in September. You can read the resultats from experiments in 2011/2012 in the research report here.
In most cases, the iron was administered in combination with vinasse. Vinasse is a kind of molasses which consists of approximately 50% humic acids. Humic acids have a chelate effect, which facilitates the absorption of iron and other minerals in the body. Administering iron stimulates mite fall. Administering iron with vinasse results in even higher mite fall.
In addition to the positive side effects, vinasse also has adverse effects on bees and bee colonies. These manifest themselves if too much vinasse is administered.
Iron has a positive influence on the individual bees and on the bee colony if, and only if, the iron is administered in the correct quantities, in the correct manner and at the correct time. By administering an iron supplement, the beekeeper does not have to take other measures to combat the Varroa mite.
It is now clear what can happen when iron is administered to bee colonies. Based on the observations reported by beekeepers we have investigated the cause of these effects.
Click hereunder to download the research hypothesis (only available in dutch), formulated in 2011 prior to the experiments. Here you can read about how Science in Water was inspired to administer iron and what, at the time, were seen as possible causes relating to the problems with metabolism of iron in bees.