Parasites, viruses, bacteria and fungi can be the source of bee diseases. A number of these pathogenic organisms are subject to mandatory reporting so as to prevent them spreading any further.
The list of diseases below subject to mandatory reporting, is established by the Royal Decree of the 7th of March 2007 concerning the fight against the contagious diseases of bees.
In case of a suspicion of an outbreak of one of these animal diseases, the beekeeper must report this immediately to the Provincial Control Unit (PCU) of the Federal Agency for the Safety of the Food Chain (FASFC).
An important pathogenic organism for our honey bees is the varroosis destructor. This mite was first noticed in Belgium in 1984 and has since spread across the whole country.
Just before the closing of the brood, the parasite lodges in the brood cells so as to multiply. He feeds on the hemolymph, the ‘blood’ of the larvae, as a result of which the young bees are weakened or deformed.
The fight against the varroosis mite demands an integrated approach. Every year the Federal Agency for the Safety of the Food Chain (FASFC) draws up a fight advice concerning varroa, which is distributed through the beekeeper associations. In this advice one does not only deal with the treatment through veterinary medicine, but also with biotechnical methods such as the removal of the drone brood.
The tracheal mite or acarapis woodii mite is a parasite which penetrates into the breathing openings of the young bees and procreates in the upper airways or trachea. He feeds himself with the hemolymph by pricking small holes into the wall of the air tube. The excrements of the mites stay behind in the trachea, as a consequence of which they are blocked. The bees become weakened and die.
American foul brood
American foul brood is caused by the bacterium Paenibacillus larvae subsp. larvae. It is a brood disease, which means that only the young larvae become sick. The extraordinary thing about the bacteria is that in extreme circumstances they form spores, which even in extreme conditions can survive for years.
The bee larvae can absorb these spores in their food. Once in the intestinal tract, they germinate once more into bacteria and break through the intestinal wall to feed themselves on the hemolymph and to multiply. Inevitably, this leads to the death of the larva, after which the bacteria form spores again in order to be able to survive. Consequently, the bees which clear away the remains of the larvae, also get contaminated and spread the disease within the bee hive.
It is no longer permitted to treat the disease with medicine, but it has to be enclosed, amongst others by putting up a surveillance zone around the focus of infection. The Federal Agency for the Safety of the Food Chain (FASFC) decides whether the affected bee colonies have to be exterminated and burned, or that reorganization measures have to be imposed (see article 13 of the Royal Decree of the 7th of March 2007).
European foul brood
Also in the case of the European foul brood it concerns a bacterial contamination (Melissococcus plutonius).
Just as with the American foul brood, the disease is not to be treated with medicine. The Federal Agency for the Safety of the Food Chain (FASFC) decides whether the affected bee colonies have to be exterminated and burned, or that reorganization measures have to be imposed (see article 13 of the Royal Decree of the 7th of March 2007).
Small hive beetle and tropilaelaps infestation of honey bees
Currently the small hive beetle or Aethina tumida and the tropilaelaps infestation of honey bees do not yet occur in Europe.
The small hive beetle can fly across a distance of more than 10 km. When he gets into a bee hive, he lays his eggs in cracks and crevices. The larvae destroy the brood nest and consume the honey, the larvae and the pollen. The colony withers away and the polluted honey is no longer edible.
The tropilaelaps infestation of honey bees parasites just as the varroosis mite on the larvae of the bee and feeds on the hemolymph of the brood, so that the young bees become weakened and deformed.
In order to prevent the spread on the European territory, the reporting of these two pathogenic organisms is mandatory, in case they would turn up. Also many import measures have been taken. E.g. only bee colonies and bumble bee populations may be imported from biologically safe centres. In addition, no queens may be imported from countries where one of these plagues is prevalent.