When we think of bee nests, we often think of a giant hive, buzzing with social activity, worker bees and honey. But scientists recently discovered a rare, solitary type of bee that makes tiny nests by plastering together flower petals.Each nest is a multicolored, textured little cocoon – a papier-mache
husk surrounding a single egg, protecting it while it develops into an adult bee. “It’s not common for bees to use parts of plants for nests,” says Dr. Jerome Rozen of the American Museum of Natural History of the unexpected find. His team stumbled across the nests of the Osima (Ozbekosima) avoseta bee in Turkey. Oddly enough, another team discovered the same bee and flowery nests in Iran on the same day. The two teams published their research together in the American Museum Novitates.
These Thumbelina-like nests are a fascinating natural work of art, but they’re
also key to understanding more about how the roughly 20,000 species of bees live.
“There’s a demand for biologists to know bees nowadays,” Rosen says. “They are the foremost animal pollinators of plants, and tremendously important for maintaining ecosystems – not only crops but also for conservation.”
To learn more, the scientists watched the busy mama bees. Building a nest takes a day or two, and the female might create about 10 nests in total, often right next to each other. To begin construction, she bites the petals off of flowers and flies each petal – one by one – back to the nest, a peanut-sized burrow in the ground.
She then shapes the multi-colored petals into a cocoon-like structure, laying one petal on top of the other and occasionally using some nectar as glue. When the outer petal casing is complete, she reinforces the inside with a paper-thin layer of mud, and then another layer of petals, so both the outside and inside are wallpapered – a potpourri of purple, pink and yellow.
These meticulous shells are just over a half-inch long and usually will house just one tiny egg. To prepare for her offspring, the mother collects pollen and nectar, which she carries back to the burrow in a nifty part of the digestive
tract called the crop. She deposits this gooey blob of nutritional goodness in the bottom of the flower-petal nest. Then, she lays the egg, right on top of the gelatinous blob.
At this point, it’s time to seal in the egg. The mother bee neatly folds in the inner layer of petals, smears a paper-thin mud layer and then folds the outer petals. The casing is nearly airtight, which helps protect the vulnerable egg (and later larva, then pupa) from flooding or excessive dryness or hoofed animals.
In only three to four days, the egg hatches into a larva. When it finishes feasting on the nectar, the larva spins a cocoon (still inside the shell, which has hardened into a protective casing by this point) and then hangs out. Rosen says he isn’t sure whether it spends the winter as a larva or as an adult. But at some point the creature’s tissue begins to restructure itself, and it transforms into an adult. Come springtime, the adult bee emerges from its flowery bower.
Then, the cycle starts all over again. (All photo courtesy of Jerome Rozen/American Museum of Natural History)