Lifting up a rock this fairly fresh leafcutter bee nest was revealed. The bees cut almost perfect circles from leaves mainly in the Rosaceae family, to create these tubular nests. There are hundreds of old apple trees at the site, which are in the Rosaceae family, and I would bet this nest is made from apple leaves. They lay eggs in these tubes, each egg provisioned with a ball of pollen. As time passes, the cut leaves turn brown of course. It is quite a creation for a small bee to make!