Imagine finding a plate-sized tick on your person. That’s the rather disturbing — and epic — analogy Ontario’s Ministry of Agriculture, Food and Rural Affairs gives to offer a visual understanding of the size of a varroa mite compared to its host, the beloved bee.
Though not a tick, Varroa destructor are of the class Arachnida, (along with spiders, scorpions and other eight-legged wonders), and pose huge economic challenges to beekeepers worldwide. The mites feed on the body fluids of both adults and developing brood, leading to losses of energy, growth defects, increased disease susceptibility, and, in too many cases, complete hive mortality.
Synthetic and ‘naturally occurring’ chemicals are most often used to manage varroa mite populations, but the industry is starting to see resistant populations. Other methods, including physical changes to the hive, and breeding for bees who remove damaged brood have shown promise. And now, scientists based out of the Czech Republic have developed a relatively easy, beginner-friendly approach to a method originally studied in the 1970s — temperature.
”Our goal was to create a reliable method for treating Varroa without using any chemicals,” inventor and co-founder, Roman Linhart, said in a release. “It has been known for several decades that the Varroa destructor mite is extremely sensitive to increased temperature. We applied this knowledge and created a Thermosolar hive.”
The Thermosolar Hive consists of an outer cover, thermosolar ceiling, thermosolar super and varroa bottom. During treatment, the outer cover is removed, and the thermosolar ceiling slowly heats the bee colony and honeycombs to temperatures between 40°C(104°F) and 47°C (116.6°F). It takes about two hours for the hive to reach those temperatures, and another 150 minutes between those temperatures to kill mites.
“By a single heat treatment at least 80% of the mites are killed,” co-founder Jan Raja wrote us in an email, adding that these are the mites on the brood — those who cannot escape the temperature change.
Older bees, when exposed to the thermosolar treatment, tend to move to lower portions of the hive, where it’s cooler. Mites infecting them, and those on bees outside the colony, are protected from the heat, and can survive. But, it doesn’t take long for those mites to stop feeding, and move to the brood to reproduce.
“Those mites return to the brood in five days in average to multiply themselves,” wrote Raja. “Therefore it is enough to repeat the treatment 7-14 days later, killing all the mites completely. Effectiveness of both treatments is 100%, mites can infest the colony only from reinvasions coming from not treated colonies.
When the Thermosolar Hive isn’t offering a short-term, high-temperature treatment, the long-term thermal system is at work, which the scientists say “increases the long-term thermal well-being of the colony,” and “speeds up the spring development by up to two weeks.”
“Furthermore,” according to Linhart, “long term thermal support helps increase the honey amounts brought. That is because bees, which would otherwise have to stay in the hive to heat the brood, can fly for nectar flow.”
In hot climates, or on hot summer days, the thermosolar window can be shaded.
After twelve years of hard work and field testing, the hives, which cost around 650 USD, are available to purchase through the crowdfunding page. And, if the demand from North America is high enough, wrote Raja, the continent may see its own manufacturing facility.