Wild bees, nesting in Argentinian crop fields, were recently found constructing nests entirely made of the flimsy plastic packaging material left on farms. From 2017 to 2018, researchers at Argentina's National Agricultural Technology Institute crafted wooden, artificial nests for wild bees. Unlike bee species that have a large hive with queens and workers, wild bees burrow into nests to individually lay larvae. The constructed nests fit together like long rectangles with a narrow, hollow opening that allowed wild bees to crawl inside and fill it with cut leaves, twigs, and mud.
Sixty-three wooden nests were constructed, and three were found lined entirely with plastic. Similar in size and shape to a fingernail, the bits of plastic had been carefully cut by bees and arranged in an overlapping pattern in their nests. Based on the material, researchers think the plastic may have come from a plastic bag or film, which has a similar texture to the leaves bees typically use to line their nests.
Of the three plastic nests, one had not been finished, meaning the bee did not use it to lay her larvae. In the remaining two, one larva died and the other was not found, leading the researchers to believe it survived.
This new research, published in the journal Apidologie, documents the first time bees have been seen making nests only out of plastic, but for years scientists have known bees were incorporating plastic into their building materials.
In 2013, a paper published in Ecosphere outlined how bees were using plastic films and foams to line nests in urban areas throughout Toronto, Canada. Similar to the bees in Argentina, the wild bees observed in Canada cut pieces of plastic that resembled the leaves they commonly use.
Notably, the Canadian study found it wasn't just flaps of plastic bags the bees were using. Plant resins, which can be fashioned into anything from gum to latex, often bind a bee's building materials together. But some individuals, they observed, were hauling a plastic-based caulk back to their nests to use instead.
Both studies noted that more research needs to be done before scientists can outline the potential impact plastic might have on bees, but the nest building shows that bees are highly adaptive to changing environments. In both places, leaves were readily available as a building material.
