Natural predators such as birds, beetles and spiders provide an effective alternative to the use of pesticides in fields by reducing pest populations and increasing crop yields, according to a study published on March 6, 2024.
Biocontrol
Biodiversity collapse, water and soil pollution, health risks: the massive use of chemical pesticides in agriculture has experienced negative consequences. Researchers who publish in a journal Proceedings of the Royal Society Banalyzed existing studies looking at the alternative effectiveness of a form of ‘biocontrol’ based on predators naturally present in fields.
“Predators reduced pest populations by an average of 73% and increased crop yields by an average of 25%.“, concludes this meta-analysis.”Our study highlights that predators indirectly support yields and provide vital ecosystem services that could persist under current climate change.“, write scientists based in Brazil, the United States and the Czech Republic.
“Natural predators are good means of pest control”
However, they did not directly compare their effectiveness with the effectiveness of synthetic pesticides, which was not evaluated in the study. But”many other articles demonstrate the damage pesticides do to ecosystems and biological control,” notes Gabriel Boldorini, a PhD student at Brazil’s University of Pernambuco and lead author of the study.The message is that natural predators are good means of pest control and their maintenance is essential to ensure this control in the future with climate change.“, he emphasizes.
The researchers found that the effectiveness of predator presence was greater in areas with greater variability in rainfall throughout the year – a characteristic that will increase in certain areas as climate changes.
Another conclusion: biological control by multiple species of predators is no more effective than control by a single species. “In general, the more species there are, the better ecosystems function. But there are exceptions“, notes Gabriel Boldorini. For biocontrol, the presence of several species of predators certainly makes it possible to focus on the diversity of types of pests at different stages of their development. On the other hand, however, predators can enter into competition with each other. , even each other.