National Geographic : 2010 Dec
PHOTOS: JEROME G. ROZEN, JR. BROOD CELLS ; JOHN S. ASCHER BEE WILD Flower Beds Call it ikebana for insects. Female Osmia avosetta bees, scientists have recently discovered, arrange flower petals to form unique nests that swathe their larvae in nutrients and warmth for the winter. Biologists had never seen this species' creations until last year, when two research groups working simultaneously found and excavated nests at mountain-slope sites in Turkey and Iran. Together they report that the female of this solitary bee--- which eschews hive life---digs a shallow tunnel in loose ground with room for one or two chambers, or brood cells, each up to two inches deep. She then papers the cell walls with overlapping petals flown in one by one from nearby fields, gluing two layers together with a thin coat of mud. Finally she stocks each chamber with larval food---a slurry of nectar and pollen---deposits an egg on top, folds the inner petals over, seals the door with damp soil, and ends with another petal fold. The process can take up to two days, the scientists say. The cell soon hardens into a tough nugget that's humid inside and predator- and water-resistant outside--- an ideal winter shelter come drought or flood. A petal nest's loveliness is no doubt lost on the larval bee, which develops in the dark and, without eyes at that stage, can't see regardless. And while scientists appreciate the artistry, says co-discoverer Jerome G. Rozen, Jr., of the American Museum of Natural History, "we're most intrigued by its beauty as an evolutionary mechanism for protecting offspring." ---Jennifer S. Holland HOUSE BEAUTIFUL A female bee (below) brings a petal to her unfinished nest. Above are the products of several bees' efforts: brood cells with petal shingles.