Varroa Destructor

By | July 5, 2012

A few weeks back, I posted about a large infestation of Varroa mite in the Rua Tekau colony.

The nasty Varroa destructor mite

The nasty Varroa destructor mite

The Varroa mite is aptly named Varroa destructor.

The Varroa mite lives within the colony, breeds inside capped larvae cells and feeds off bee larvae.

This can kill the bee larvae, but when the Varroa mite emerges from the larvae cell current research suggests it also carries a virus called Deformed Wing Virus (DWV).

"Stumpy" was never up for leisurely Sunday flights, displaying the results deformed wing virus

“Stumpy” was never up for leisurely Sunday flights, displaying the results deformed wing virus

Unsurprisingly, this virus deforms bees’ wings causing crumpled, unusable wings. To top that off, the adult mite sucks the blood of adult bees. Its numbers can multiply logarithmically, as we found with the Rua Tekau colony. It can wipe out a colony very quickly.

Unfortunately Varroa inhabits almost every bee colony worldwide, so Varroa management is required (rather than elimination) due to its widespread, virulent and robust nature.

Varroa is not yet in Australia and some parts of New Zealand, but unfortunately is only a matter of time. The global transport of bees doesn’t help controlling its spread either.

Recent studies in Hawaii have tracked the spread of Varroa infestation, and its effect on honey bee colonies, as it enters the islands. This research has increased scientist’s and bee keeper’s understanding of the mite, and how it affects colonies – and contribution towards Colony Collapse Disorder (CCD).

We can only hope that with increased research and understanding, we can eliminate or better control this foul parasite.

As far as the Rua Tekau colony is concerned, we need to continue our disease management techniques, which is a major part of being a responsible beek.

We will probably continue weekly icing sugar dusting, which force the bees to groom themselves and knock the mites off adult bees, through the floor and out of the hive. But, this isnt a long or medium term solution.

We will also promote the increased laying of drone bees in the hive. Drones have larger larvae, and a slightly longer pupating period which Varroa are attracted to. We can clear out the developing drone brood before they hatch, in an attempt to reduce the mites laid within.

If things are really bad, we might resort to chemical methods – but we would have to remove the honey stores to prevent them being tainted. Chemical treatment generally only happens at the end of summer, to prepare the colony for winter. However, as we have had an unusual year with not much honey produced, early chemical treatment might be the best medicine to increase the colony health.

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