City bees turning to plastic waste as hive-building material

At least two urban bee species have turned to their city environment for nest-building materials, using plastic waste to build hives, Canadian scientists say. A study at Ontario's University of Guelph, reported in the journal Ecosphere, reveals some bees are using bits of plastic bags and plastic building materials to construct their nests. The finding is significant because it shows bees' resourcefulness and flexibility in adapting to a human-dominated world, lead study author Scott MacIvor said. "Plastic waste pervades the global landscape," he said. Although much research has been done on adverse impacts of the material on species and the ecosystem, few scientists have observed insects adapting to a plastic-rich environment, he said. "We found two solitary bee species using plastic in place of natural nest building materials, which suggests innovative use of common urban materials." One species, Megachile campanulae, was found to occasionally be replacing plant resins -- its normal hive construction material -- with polyurethane-based exterior building sealant, such as caulking, in its brood cells where larva are reared, the university reported Tuesday. Another, Megachile rotundata, an alfalfa leafcutter, was using pieces of polyethylene-based plastic bags to construct its brood cells, the researchers said. In both cases, the researchers said, larvae successfully developed in the plastic-lined nests. In fact, the bees emerged parasite-free, suggesting plastic nests may be a physical barrier to parasites, they said. "The novel use of plastics in the nests of bees could reflect the ecologically adaptive traits necessary for survival in an increasingly human-dominated environment," MacIvor said.