Bees and wasps have long been admired for their architectural prowess: their intricate nests and hives are marvels of engineering. Even more impressive, however, is the fact that these insects, despite their different evolutionary origins and the different materials they use for construction, have independently developed remarkably similar technologies.
What bees and wasps have in common is the creation of hexagonal cells. This configuration provides an optimal ratio of strength to cell area, while reducing the need for construction materials. However, a problem arises when the ideal hexagonal structure cannot be achieved.
To study this problem, researchers led by Dr. Michael L. Smith, associate professor of biological sciences at Auburn University and a member of the Max Planck Institute for Animal Behavior, collected nest images from around the world that showed worker and reproductive cells in the same comb. Using specially developed software, the experts meticulously extracted measurements per cell from an impressive 22,745 cells.
The study showed that as the discrepancy between worker and reproductive cells increased, the insects began to build non-hexagonal cells. They were mostly 5- and 7-sided cells built in pairs, with the 5-sided cell being created on the worker side and the 7-sided cell on the reproductive side.
By studying ten species, Smith and his colleagues found a common pattern. Despite an evolutionary gap of 179 million years, bees and wasps appear to have independently arrived at the same architectural solution to this scaling problem. Even though they have different building materials and independent origins of hexagonal cells, they use the same structural approach.
The researchers developed a mathematical model that predicts the number of non-hexagonal cells that should be included in a structure based on their findings about differences in cell size. Some species consistently outperformed the model’s expectations by including medium-sized cells in the transition region, reducing the need for non-hexagonal cells.
This observation is striking given the known affinity of these insects for hexagonal structures. Just as sharks and whales created similar body structures to adapt to aquatic environments, bees and wasps build hexagonal cells for their nests.
Some species of honeybees and wasps build hexagons of two different sizes: the smaller cells house the workers and the larger cells house the chicks and mothers. This mismatch in cell sizes poses an important architectural problem. How can these two hexagons of different sizes fit seamlessly into a single ridge?
In species such as Metapolybia mesoamerica, the architectural puzzle did not have to be solved. Both worker and reproductive cells were the same size. On the contrary, in species such as Apis andreniformis, reproductive cells were 2.7 times larger than worker cells.
Bees and wasps have proven to be remarkable architects, consistently approaching complex construction problems. Their independent approach to the same architectural solution demonstrates their ingenuity and adaptability.