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Varroa mites: part one

Varroa destructor is the scientific name for an arachnid parasite that can only reproduce in the presence of honey bees. These parasites infiltrate a bee colony by means of external introduction and once they are present, become a burden on a colony. Normally, parasitic relationships are not devastating, as the parasite needs the host to survive. However, in the case of varroa mites, they destroy their hosts. The mites can transmit several types of diseases, that ultimately destroy a bee colony, either directly or indirectly by weakening the bees to the point that they are no longer able to carry about the normal working functions. Varroa mites are relentless but not invincible, that is where the beekeeper comes in.

To give you a bit more perspective about the nature of the mites let me first describe the size of the mite. The mites are normally between 1 and 2 mm long and about the 2 mm wide. Honey bees, in comparison, are on average 14 mm long. That means a varroa mite is approximately 15% the size of a honey bee. That would be like a person who is 6 feet (183 cm) tall having a 11x11 inch (27x27 cm) sized tick stuck to the body, between the shoulder blades where it can not be removed. YUCK! Once attached, the mites do not let go unless they are dead.

Honey bees, have not yet learned how to remove the mites from the bodies of other worker bees. The only chance the bees have, is to remove infected larva from the hive BEFORE the mites can attach and reproduce. This behavior, known as Varroa Sensitive Hygiene or VSH, has been observed in some colonies, and is becoming a popular breeding aspect especially in the United States. As a beekeeper, I too would prefer that my bees learn to clean up house so that I do not need to treat them with formic acid, but this is a process I am not yet prepared to begin.

Some beekeepers propagate the usage of chemicals, medicine, and organic methods to help the bees control varroa mites. The advantage is that these methods are tried and trued, showing higher survival rates and lower disease rates. The disadvantage is that the weaker bees are left to pass on their genetics thus creating more weaker bees. In other words, nature is not allowed to run its course. I am currently stuck in the middle. My preference would be, as stated above, to let the bees duke it out with the mites, the strongest bees will survive. The weaker bees die off, taking the parasites down with them. The problem with this is: I would be alone in my efforts. The only way VSH can be successful, is if several beekeepers whose bees are within flight range of one another use the exact same methods. All the beekeepers I know want honey, lots and lots of honey. Implementing VSH would certainly mean that several (maybe up to 90%) of the colonies would die in the first year.

As for now, I will try to limit the amount of formic acid (and if need be oxalic acid) treatments to the bare minimum. The last thing I want, is that the mites build up a resistance to the acid. On a side note: I placed the varroa drawers into all three hives for diagnosis of the mite content last Tuesday. This past Saturday, I had a look, and was happy to find ZERO mites. Maybe I will be lucky and I will be able to get away with 1 to 2 treatments, at least I hope so. More to follow in a later post.


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