A new study by scientists has found that a common pesticide widely used in global agriculture changes the gene expression of bumblebees at the molecular level and interferes with their ability to reproduce, which may pose a long-term threat to crop pollination and food security.
Bees and other pollinating insects are the cornerstone of modern agriculture. They help reproduce a large number of fruit, vegetables and seed crops, ensuring a stable supply of food on the human table. However, pesticides used to protect crops from pests can harm this critical ecological service if they harm pollinators.
The chemical substance causing concern this time is sulfoxaflor. This pesticide was put into use in 2013. It mainly targets sucking pests such as aphids. It is widely used in crop fields such as corn and soybeans and has remarkable effects in preventing and controlling crop pests. However, studies have shown that sulfoxaflor is toxic to bees, and the scientific community has been tracking the impact of low-dose exposure on bee reproduction and molecular-level mechanisms.
A research team from the Georgia Institute of Technology in the United States further confirmed in a new study that low-dose sulfoxaflor exposure not only interferes with the reproduction of bumblebees, but also significantly changes the expression activities of multiple genes in their bodies. The study was funded by the U.S. Department of Agriculture. The researchers exposed worker bees to low levels of sulfoxaflor in a controlled environment and detected changes in gene expression in different tissue parts.
The results showed that the bumblebee's ovarian tissue was the most affected site, with dramatic changes in gene activity. The research team pointed out that this type of ovarian gene expression disorder may reduce the overall reproductive success rate of the bee colony, which will contribute to the decline in the number of bee colonies in the long term. In order to characterize this effect in detail, the researchers quickly frozen bumblebee tissues in the experiment, then analyzed the changes in gene activity after pesticide exposure, and used computational models to identify the most significantly affected biological processes.
Michael Goodisman, one of the leaders of the research team and a professor in the School of Biological Sciences at Georgia Institute of Technology, said that what is unique about this study is that it directly links molecular changes in gene expression to actual ecological consequences for individual bees and bees. This kind of cross-scale evidence is still very rare in pesticide risk assessment.
The research also highlights the core problems facing today's agriculture: on the one hand, pesticides are needed to effectively control pests to ensure yields and farmers' profits; on the other hand, they must minimize damage to non-target, beneficial insects such as bumblebees. The study's first author, Sarah Orr, led the experiments during her postdoctoral work at Georgia Tech and is now an assistant professor at the University of Tampa. She emphasized that the goal of scientific research is to find workable compromises between pest management and insect conservation to safeguard global food production that relies on pollination systems.
Researchers point out that keeping bee colonies stable is crucial to ensuring pollination. If bee colonies have insufficient offspring due to factors such as pesticide pressure, crop pollination efficiency will inevitably decrease, affecting yields and ecosystem health. scitechdaily
It’s important to note that sulfoxaflor is just one of multiple stressors faced by bumblebees. In addition to pesticide exposure, environmental changes such as global warming and frequent extreme heat events are becoming increasingly important stressors. Scientists hope that by in-depth understanding of how pesticides such as sulfoxaflor affect bee physiology and behavior at the molecular level, they can provide farmers and regulatory authorities with a more scientific basis for decision-making, ensuring crop returns while better protecting these pollinators that provide key services to agriculture and natural ecosystems.