Common eastern bumblebee collecting nectar
Nature Photo Library/Alamy
In the first study of its kind, scientists have found that feeding honeybees small pieces of absorbent hydrogel increases their chances of surviving exposure to toxic pesticides.
As important pollinators, honeybees play a vital role in both wild plants and cultivated crops, but the pollen they ingest is often contaminated with chemicals that can have devastating biological effects on bees, including promoting colony collapse or causing almost immediate death.
Previous research has shown that particles of hydrogel (a soft, non-toxic, highly absorbent material) mixed into soil can bind and trap neonicotinoids, a type of insecticide that is widely banned in Europe but still used in the U.S. This led Julia Caselto and her colleagues to test whether small pieces of hydrogel could neutralize the insecticide in the bodies of common eastern bumblebees (Bumblebee).
“To my knowledge, no one has ever done this,” said Caselt, who conducted the research while at Cornell University in New York.
The researchers first mixed hydrogel particles into sugar water that were small enough to pass through the bees’ digestive tracts but too small to migrate to other parts of their bodies. After the bees drank the solution, the researchers fed them high doses of an insecticide. The hydrogel-treated bees were 30 percent more likely to survive than those that weren’t.
When researchers exposed honeybees to an insecticide that disrupts their nervous systems but does not kill them, the hydrogel reduced the bees’ symptoms: The bees that received the gel were able to forage and walk better, flap their wings faster, and were healthier than those that did not.
Bees eventually excrete the hydrogel particles, necessitating continuous administration of an antidote, making the treatment impossible for wild bees, but it could be a promising option for managed bees, such as those used for honey production and crop pollination.
“These particles can be incorporated into pollen putties or sucrose feed already used in managed honeybee colonies,” Caselto says, “and the hope is that when the bees go out into the field and are exposed, they will be less sensitive.”
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