HAPPY MOTHER'S DAY 2010

Like a Delicate Wallpaper, Busy Bees Use Flower Petals For Nest

(paraphrased)_ originally written by Kathleen Masterson

May 6, 2010

When we think of bees 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.

Jerome Rozen/American Museum of Natural History

This nest of the O. avoseta bee, a variety of bee not seen in the western hemisphere, is made of flower petals that holds a single egg.

Each nest is a multicolored, textured cocoon — a papier-mâché-like husk surrounding a single egg, protecting it while it develops into an adult bee.

'It's not common to us to see a bee use parts of plants for nests,' says (paraphrased), Dr. Jerome Rozen of the American Museum of Natural History, of the unexpected find. His team stumbled across the nests of the Osmia (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.
Multiple flower-lined nests of the O. avoseta bee are nestled in the ground.


Jerome Rozen/American Museum of Natural History

One mother bee may make around 10 nests, often nestling the single-cell berths near each other.

These nests are a fascinating natural work of art, and 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 female bees. Building a nest takes a day or two, and the female bee 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.

Jerome Rozen/American Museum of Natural History

A bee closely related to O. avoseta bites off a flower petal with its mandibles.

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 adhere to one another, in what becomes a potpourri of purple, pink and yellow.

Jerome Rozen/American Museum of Natural History

Peeling back the outer layer of flower petals reveals the paper-thin mud layer.

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.

A closeup of an egg, laid on top of nutrients.


Jerome Rozen/American Museum of Natural History

The mother bee lays a single egg in the flowery bower, right on top of a nutritious deposit of nectar and pollen.

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.

When the cycle starts all over again.