When it comes to 3D printing, the sky is the limit. As 3D printing technology continues to advance, applications can be as far reaching as airplane and automobile parts to medical devices and even anatomically correct, biocompatible models. Although 3D printing technology is developing at a rapid pace, the technology itself is not new. It emerged in the 1980s as a means of creating rapid prototypes. In recent years the applications for 3D printed models have evolved with the available hardware, software, and printable materials. Evolving technology, paired with the creative and innovative minds of scientists, engineers, and physicians, has been the launching pad for developments within 3D printing technology specific to healthcare. One way 3D printing technology is poised to create better patient outcomes is in creating an anatomically and patient-specific models to aid in surgery and medical procedures. With the capability to 3D ...
It’s amazing, but true! As humans increase their use of polymermaterials in construction, some species of wild bees seem to be following suit. Canadian scientists from York University and the University of Guelph have studied and documented two ways plastic materials have been used by wild bees. The article, published in Ecosphere, explains:
Plastic waste pervades the global landscape. Although adverse impacts on both species and ecosystems have been documented, there are few observations of behavioral flexibility and adaptation in species, especially insects, to increasingly plastic-rich environments. Here, two species of megachilid bee are described independently using different types of polyurethane and polyethylene plastics in place of natural materials to construct and close brood cells in nests containing successfully emerging brood. The plastics collected by each bee species resembled the natural materials usually sought; Megachile rotundata, which uses cut plant leaves, was found constructing brood cells out of cut pieces of polyethylene-based plastic bags, and Megachile campanulae, which uses plant and tree resins, had brood cells constructed out of a polyurethane-based exterior building sealant. Although perhaps incidentally collected, the novel use of plastics in the nests of bees could reflect ecologically adaptive traits necessary for survival in an increasingly human-dominated environment.
Studying the behavior of urban bees and wasps, the scientists used so-called trap nests, or nests build by cavity-nesting bees in man-made cavities, such as drilled wooden blocks. In such a nest, the brood cell series are laid in a row, forming a nesting gallery. To make the study, more than 200 trap nests were placed in locations around Toronto. After collecting and inspecting these nests, the scientists found the presence of non-natural materials.
Polyurethanes Present
One analyzed nest was built by a wild bee, Megachile campanulae, which is native to Southern Ontario. It collects and uses plant resins (such as pine sap) for nest-building. Some brood cells in this nest appeared different in color and consistency. The cell walls were analyzed by FTIR spectroscopy and X-ray microanalysis using Field Emission SEM (Scanning Electron Microscopy), and compared to other natural brood cells, as well as chemical reference materials. The elemental analysis and FTIR spectra have shown the strong presence of polyurethane polymers, used in sealants and caulking that commonly are applied to the exterior of buildings.
In the nest of a different bee, Megachile rotundata, the scientists have found some brood cells in which fragments of polyethylene plastic film (such as used in grocery bags) replaced about 20 percent of the cut leaves normally used by this type of bee to build the cell walls. It appeared that while building the nest, the bees would start with a plastic fragment and finish with the leaf pieces, which means that the leaves were available for construction. The same thing happened with polyurethane polymer, which was incorporated along with the natural resins, meaning that “the use of polyurethane-based sealants might be incidental and not due to a lack of natural resin options.”
Still Not Common
The use of plastic bag fragments as building material was not very common and over 2 years was found in less than 1 percent of all analyzed nests. The scientists even took a close look at the teeth markings along the plastic fragments, which were coarser than the markings on the natural leaves, “suggesting the use of plastic bags represented an aberrant behavior.” What were these bees thinking?
The use of plastic materials in bee nests might provide some advantage in protecting the bees from the parasites (which were found in other studies using plastic nest traps). In the current study, the male bees that emerged from polyethylene-containing brood cells were also parasite-free. However, substituting leaf pieces with plastic bag fragments was structurally disadvantageous, as the plastic did not adhere well to the leaves comprising the brood cell. Could it be that the bees were just exploring new construction materials? We can certainly relate to that.
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