Two species of leaf cutting bee were found to harvest plastics from their environment and use them to seal the brood chambers in their nests, the places where they lay their eggs and young larval bees develop. In both cases, the plastics resembled the materials that the bees typically collected. In one case the plastic was from a plastic shopping bag and in another it was exterior house sealant.
Although the bees used the plastics, they were found in less than 1% of cell walls constructed. Nevertheless, the plastic pieces did not adhere to the masticated leaf fragments and were flaking off. Yet in the bees in chambers containing plastics matured and emerged successfully. When plastic straws have been used to rear leaf-cutter bees, the young were not successful, usually due to moisture retention that lead to mold.
It’s hard to say whether this discovery is positive or negative. According the authors, the ability of the bees to use plastics displays flexibility and adaptation to a world that has ever-increasing levels of plastic in the environment. Yet there could be consequences of using plastics if they alter bee development, although this was not noted in this study. At any rate, plastics are here to stay, and insect adaptation to their presence is likely to become increasingly necessary.
J. Scott MacIvor and Andrew E. Moore 2013. Bees collect polyurethane and polyethylene plastics as novel nest materials. Ecosphere 4:art155. http://dx.doi.org/10.1890/ES13-00308.1