Posted by: Han Truong | Sacramento Bee
A recently published study by researchers at the University of California, Davis showed that pesticides can have long-term effects on the health of bees, slowing their reproduction rate.
According to results published in the Proceedings of the National Academy of Sciences, it may take several generations of bees to recover from a single pesticide application.
Here’s a rundown of the research and what you can do to save the bees.
What is research and its findings?
The study was conducted by exposing blue garden bees to imidacloprid, a common insect control chemical, at the recommended amount on the label. According to a UC Davis article, bees were given one application for two years, which is the standard exposure level.
“Repeated exposure over two years had an additional negative effect on individual fertility, resulting in a really dramatic decline in population growth,” said Clara Stuligross, lead author of the study.
The researchers concluded that bees that were exposed to insecticides, both larvae and adults, produced 44% less brood. And in bees that were exposed to the chemical for two years in a row, population growth rates dropped 72% compared to bees that were not exposed to any level of exposure.
The study looked at only one pesticide
The study was based on the use of imidacloprid, a nicotine-mimicking insecticide that is toxic to insects. This chemical is the most widely used for insect control.
Stuligross, a UC Davis doctoral student in ecology, said that because there are a lot of insecticides on the market, you can’t extrapolate the study’s findings. But she believes that the effects of imidacloprid on bees will be reflected in similar types of pesticides.
“It also helps us understand the overall consequences of repeated exposure to pesticides,” she said.
The importance of bees
According to the Planet Bee Foundation, a nonprofit environmental education organization based in San Francisco, bees are the most efficient pollinators in the world. As pollinators, these buzzing insects help plants survive, which in turn provides us with food, wildlife, and the environment.
“They are really important to our ecosystem,” Stuligross said. “And so understanding how pesticide exposure affects bees over time is important to understanding how to actually maintain them and how to continue to support our healthy and sustainable food systems.”
What can you do
Stuligross said the most important thing humans can do is to minimize the use of pesticides on bees as much as possible.
This means that you cannot use these chemicals during the flowering of crops and flowers, because bees are usually attracted to plants that bloom with nectar and pollen.