Varroa destructor is a small creature causing big problems. But what exactly is Varroa destructor, and why should you care?
What is Varroa destructor?
Varroa destructor is a species of mite. They have eight legs, are 1-2mm in length and width and are a red-brown colour. They are a parasite that attack honey bees, attaching to them and sucking their hemolymph (the circulatory fluid in arthropods, analogous to blood in vertebrates). This parasitic behaviour causes bees to have reduced weight, reduced lifespans and weakened immune systems. In addition, mites often transmit deadly viruses to bees. Varroa destructor infestation leads to reduced honey production and often causes bee colonies to collapse. As well as affecting the apiculture industry, this has serious consequences for agricultural industries that rely on honey bees for pollination.
What areas are affected?
Varroa destructor originated in Asia, where its natural host is the Asian honey bee (Apis cerena). The Asian honey bee evolved various natural defences against the mite. However, the mite spread to the European honey bee (Apis mellifera), who did not have any natural defences. As a result the mites quickly multiplied and spread through European honey bee populations across the world. Untreated colonies (including wild hives) typically collapsed within 3 years of being infected. Today the mite is a major problem in every major beekeeping region in the world, with the exception of Australia.
How can we control it?
Scientists and beekeepers in affected regions have developed various chemical, physical and genetic engineering methods to try to control Varroa destructor. These methods are not totally effective and have various downsides, such as being expensive, labour intensive and potentially harmful to bees and humans. Progress is being made, particularly regarding genetic engineering methods, but much more research is still needed.
Australian efforts to control Varroa destructor are primarily focused on the short-term solution of preventing the mite from reaching Australian shores. This approach is working so far, but it is important that we also invest in long-term solutions to deal with the mite if it does arrive.
Why should I care?
If Varroa destructor arrived in Australia it would affect all Australians in some way. It would almost definitely lead to a significant decrease in the overall honey bee population, especially wild hives. This would be most heavily felt by the agricultural industry, who rely on honey bees for pollination of many crops. Less pollination would lead to lower crop yields, which would ultimately lead to an increase in the price and a decrease in the availability of most fresh fruit and vegetables in the supermarket. If you don’t want to have to pay more for your food, then you should care about Varroa destructor!