Test 1999 - Honey Bees

Since 1999, an abnormally high death rate of honey bees (Apis mellifera L.) has been observed in Belgium. Many studies carried out in Europe and in North America clearly highlight many factors of risk: parasites, diseases, climate, food resources, low farmland biodiversity. The honeybees collapse stigmatizes a deep uneasiness at apiarian world confronted with a more and more anthropized environment.

In this context, an exploratory multifactorial study was set up in order to discover the factors of risks which are likely to influence the vitality of the bees in Belgium. This project began in 2004 and we studied the effect of pesticides, pathologies and environment on honey bee colonies survival.

A list of pesticides including both product types used in apiculture and for the surrounding agriculture has been set up and quantification of residues of those pesticides (about 50 analytes) in honey, beeswax, bees and pollen were carried out. The pathologies were studied combining field observations, microscopic, classic microbiological and molecular approaches.

Finally, the correlation between the honeybee colonies mortality and the presence of pesticides, pathologies and the environment were analyzed.

Eighteen pesticides were detected in the hives but at very low concentration and no relationship between these chemicals and the honey bee colony mortality was observed. Concerning the pathologies, Varroa destructor, American foulbrood and Acute Bee Paralysis virus, which was the least prevalent of the detected honey bee viruses, were strongly linked with increased colony mortality. Co-infection with more than two viruses also had an appreciable negative effect on colony survivorship.