The classic wooden hive box used by beekeepers worldwide, first designed in the 1800s, is prone to temperature swings, according to a study by researchers at Queensland University of Technology in Australia. That’s bad news for the honey bees inside, who must expend energy to maintain their favored internal hive temperature. (Photo by Rebekah D. Wallace, University of Georgia, Bugwood.org)

By Paige Embry

Paige Embry

European honey bees (Apis mellifera) suffer from an astonishing array of problems—Varroa mites, hive beetles, foulbrood, chalkbrood, stonebrood, deformed wing virus, 20-plus other viruses, poor diet, predation, pesticide exposure—it’s death by a thousand cuts. A new paper in the Journal of Economic Entomology adds another knife: the typical house beekeepers provide for honey bees. It’s a wooden box based on a nineteenth century design that leaks and gains heat just like you’d expect it would. And occasionally someone comes along and takes away part of the insulation (honey). Honey bees just can’t win.

Daniel Cook is a Ph.D. candidate at Queensland University of Technology in Australia and lead author on the study,  published in March in the Journal of Economic Entomology, which examined the thermal dynamics of the traditional managed honey bee hive box. Cook says via email that the commonly used wooden hive boxes “are designed for the human first, with the bee a vague afterthought.”

Daniel Cook

While studying industrial design as an undergraduate, Cook looked at how to build a better hive box. “I had a small bee yard peppered with sensors to determine how the bee hive itself behaves thermally,” he says. “From there, the design of the hive screamed of thermal inefficiencies.” Cook and colleagues’ research on the thermal properties of typical hive boxes quantifies their leakiness and highlights the potential impacts on the bees and their keepers.

Honey bees are persnickety about the temperature of their home. It needs to be between 34.5 and 35.5 degrees Celsius (approximately 94-96 degreesFahrenheit) or it adversely impacts the brood (eggs, larvae, and pupae), so the bees work to maintain that ideal temperature in various ways, such as fanning with their wings to cool or shivering to warm.

In their study, the researchers calculated the heat loss of the boxes along with the thermal impact of certain beekeeping practices. All the experiments looked at the heat loss only from the boxes and their non-living components (honey, wax, etc.). “The reason I left bees out of this study was that there are far too many behaviours that occur in the hive for thermoregulation,” Cook says. “It is not an easily applicable constant!”

The authors compared the heat loss of a standard wooden box to a polystyrene model where the internal temperature was a honey bee-idyllic 35 C and the outside temp was 25 C. The polystyrene version’s heat loss was 23 percent of the amount lost by the wooden box. Cook notes that about half the heat loss is through the lid; therefore, “a well insulated lid could reduce stress in the hive and increase forager availability.”

Two beekeeping practices can also have a large impact on the hive’s temperature: honey extraction and cold storage of box parts (which prevents damage from various pests). A standard wooden hive consists of stackable boxes. The queen is sequestered in the bottom box where she lays her eggs. As the colony grows, boxes can be stacked on top of the base box. Only honey gets stored in the upper boxes (supers). It’s a convenient system for beekeepers who can pop off a super to extract the honey and replace it with an empty box, but that new box can lead to a lot of warming-related work for the bees. Not only is the insulating honey gone, but the authors calculate that adding supers with components that had been stored between 2 C and 5 C could require bees to expend 130,000 to 145,000 “bee minutes” to heat up the new box. That’s time that could be used for other activities, like pollinating plants and bringing home nectar to make honey.

Why do beekeepers keep using boxes that make bees expend energy in ways that aren’t useful to beekeepers? Cook offers several theories. Many beekeepers buy a beekeeping business that already has boxes, or get boxes secondhand. Plus, wooden boxes are long-lasting and cheap to fix. Changing to a new style of box could be costly. Also inhibiting uptake of better box design, Cook says, is the “yawning divide between the science and the practice of beekeeping.” Cook notes that about 9 percent of global agricultural production relies on pollination, and so, he says, “It really is time we started looking to optimise pollination systems and services from the ground up rather than using a 160-year-old honey-collection system.”

He adds, “I have put this forward to beekeepers and scientists and often hear the response ‘If it ain’t broke, don’t fix it,’ to which I always reply with my favourite Henry Ford quote: ‘If I’d asked people what they wanted, they would have said faster horses.'”

Paige Embry is a freelance science writer based in Seattle and author of Our Native Bees: North America’s Endangered Pollinators and the Fight to Save Them. Website: www.paigeembry.com.