Scientists have discovered that bees and wasps have independently developed similar architectural techniques, despite their diverse evolutionary backgrounds and the distinct materials they use for construction.
The two species share a common practice: the creation of hexagonal cells. But what’s even more intriguing is their consistent approach to solve a complex building challenge that arises when a perfect hexagonal structure can’t be achieved.
“This configuration of hexagonal cells for nests offers an optimal balance of strength and storage area while reducing the need for construction materials,” according to the earth.com. However, bees and wasps can’t always build a perfect hexagonal cell. This is especially true when both species need to accommodate differently sized hexagons within a single comb sheet.
Studying bees and wasps
Certain honey bee and wasp species construct two distinct hexagon sizes: smaller cells house workers, while the larger ones accommodate drones and queens. This discrepancy in cell sizes brings forth a significant architectural issue. How can these two different sized hexagons fit seamlessly within a single comb sheet?
To investigate, researchers gathered nest images from around the world that portrayed both worker and reproductive cells within the same comb. The team was led by Dr. Michael L. Smith, assistant professor in the Department of Biological Sciences at Auburn University and affiliate member of the Max Planck Institute for Animal Behavior.
Applying custom-built software, the experts meticulously extracted per-cell measurements from an impressive number of cells, reaching 22,745.
What the researchers discovered
According to PLOS Biology, the study revealed that in species like Metapolybia mesoamerica, a type of paper wasp, there was no architectural conundrum to unravel. Both worker and reproductive cells were identically sized. By contrast, species like the black dwarf honey bee (Apis andreniformis) presented a significant challenge, with reproductive cells being up to 2.7 times larger than worker cells.
Through this investigation across 10 species, Dr. Smith and his team found a common pattern: as the discrepancy between worker and reproductive cells grew, the insects began to construct non-hexagonal cells. These were mainly 5- and 7-sided cells built in pairs, with the 5-sided cell created on the worker side, and the 7-sided cell on the reproductive side.
The pattern appeared across all bee and wasp species that had to deal with cell size variation. This observation was fascinating, given these insects’ renowned affinity for hexagonal structures.
Bees and wasps came to the same conclusion
The team developed a mathematical model that predicts the number of non-hexagonal cells to incorporate, building upon their findings on the cell-size difference.
The researchers found that some species consistently outperformed the model’s expectations by incorporating intermediate-sized cells into the transition region, reducing the need for non-hexagonal cells.
Despite an evolutionary separation of over 179 million years, bees and wasps appear to have independently arrived at the same architectural solution to handle this scalable issue. Even with distinct building materials and the independent origins of hexagonal cells, they all adopt the same constructional approach.
“Once we were able to plot out all the data, the results were striking – you could see how the bees and wasps used intermediate-sized cells to make a gradual change, but also how consistently the non-hexagonal cells were arranged in the comb,” said Dr. Smith.
This study contributes to our understanding of how collective systems can build adaptive and resilient structures without centralized control. The construction of these combs doesn’t rely on a single “architect.” Instead, hundreds, or even thousands, of individual bees and wasps contribute to the final product.
The study, published in the journal PLOS Biology, was supported by the National Science Foundation, the German Research Foundation, a Packard Fellowship for Science and Engineering, and GETTYLABS.