Varroa Mites

Varroa mite is a main contributing factor to CCD in beehives.

Other than humans Varroa mite is the only organism that threatens mass collapse of bees and bee hives. The Varroa mite is a small tick like external parasite which attaches its self to bees before they hatch out of their eggs. It then feeds on the bees weakening the adults enough to kill them relatively quickly. This mite evolved with a special bee species that could stand it and knew how to get rid of it meaning it couldn’t kill the hive however when beekeeping became a big industry the mite started infecting other species of bee used in honey collection that couldn’t cope, this is not only bad for the bees but it’s bad for the mites because when the bees and hive die so do they. From their evolution with resistant bees the have now hurt themselves as bad as the bees. This has been killing off hives and the honey sector of economies is paying the price in all countries with the mite. First taking the scene in Japan in the 1960s the mite was making its way round the world, reaching New Zealand’s north island in 2000 and the south island in 2006. Since then it has been causing havoc where ever it resides.

Figure 1: Honey Bee in hive   Source: http://wataugaces.blogspot.co.nz/2011/04/new-formulation-for-varroa-mite-control.html

Treatment for the mite varies in many ways but they can be natural or man-made chemicals. A common treatment for big time beekeepers is chemicals, these were great at controlling the mite however as with a lot of chemicals the mites have started to become resistant to a lot of the chemicals meaning new ones are having to be formulated. The natural options also work but not as well and have to be applied more often and in harder ways which is not always economically viable for big time beekeepers. This then makes the idea of mite resistant bees become more appealing. Biologists have been working with artificial insemination of bees to cross the resistant bees with the common honey bee. These bees open the brood to get the mites out before the bees hatch and even when a mite live on them the bee still can survive. This should be the way ahead but as with a lot of things it is too expensive for most beekeepers to help fund this research and development so they are sticking to the cheaper alternative of chemicals. Bee keepers may be digging their own grave however if resilience to the chemicals carries on and the mite wipe out the non-resistant bee population.

Varroa mite is transferred from hive to hive on the back of bees. This could limit the amount of spreading it could do to a slow pace or only small distances however with bee keeping becoming bigger business beekeepers have been moving their hives large distances on trucks or boats. This has been increasing the spread of Varroa through New Zealand and throughout the world. Varroa was on the list of biosecurity threats for a long time as it’s such a threat to the economy however as it has arrived now and spread throughout the country it is no longer an issue that has to be faced on New Zealand’s boarders.

Figure 2: Varroa mite     Source: http://www.tsusinvasives.org/database/varroa-mite.html

The Varroa mite is a big worry for bees and bee keepers, with extremely low wild bee hives commercial bees are responsible for almost all pollination as well as honey. Varroa is a bigger threat than we think.