Crafty bees

In the news are these beautifully crafted nests made by bees to protect a single egg each. The solitary bee O. avosetta forms 1 or 2 of these peanut-sized nests at a time out of flower petals like papier mache. The choice of colors varies with the region: Turkish bees use blue, pink, yellow, and purple petals, while Iranian bees use exclusively purple flowers. The female bee bites each petal off the flower and flies with it to her chosen location, in a process that can take 2 days. She shapes the multi-colored petals into a pod, layering them and using nectar as glue. She reinforces the inside with a thin layer of mud, then "wallpapers" over that with more petals. "In this species, the female shingles the wall of her brood chambers with large pieces of petals or with whole petals, often of many hues." She deposits nutritional pollen and nectar in the bottom of the chamber before laying her egg inside and sealing the moisture in with more layers of petals. The petal pod hardens to protect the egg as it hatches into a larva, spins a cocoon inside where it spends the winter, and emerges as an adult bee in the spring. Despite the image of hives and swarms that come to mind, the majority of the world's 20,000 bee species are in fact not social, but solitary. These buried nests are not something bees draw attention to and are therefore a recent find. A team headed by Jerome Rozen of the American Museum of Natural History doing field work in Seklik Mevkii, Turkey, and a team headed by Claudio Sedivy of ETH Zurich doing field work in Sepidan, Yasouj region, Iran, share their research in a paper published in February (PDF document here, worth looking at for numerous additional photos). Why did the 2 teams collaborate? Because they discovered these nest-building habits independently last May on the very same day.