Insect Decline Linked to More Than Just Farming Practices

By Blake Jackson

Insects are vanishing rapidly around the world, and while agricultural intensification is often blamed, new research from Binghamton University, State University of New York, suggests the issue is far more complex. The study highlights numerous intertwined causes that contribute to this alarming trend.

Interest in insect population declines spiked after a 2017 study reported a 75% drop in insect numbers over three decades. Since then, scientists have proposed hundreds of potential explanations, but a clearer picture of the broader scientific consensus was lacking until now.

Researchers at Binghamton University analyzed over 175 scientific reviews, compiling more than 500 hypotheses and mapping out an intricate network of 3,000 links that could influence insect populations. These included factors ranging from beekeeping practices to urban development.

“It’s really hard to talk to everybody about what everyone thinks. And so instead of getting 600 people into a room, we decided to take an approach where we read every paper that’s either a review or a meta-analysis,” said Christopher Halsch, a post-doctoral researcher at Binghamton and lead author of the paper.

“The idea was to read them and extract what people say are ‘causal pathways’. For example, agriculture leads to pollution, which leads to insect population decline. Then we built a giant network out of them to see which ideas are more often connected to each other, and which stressors are most often seen as the root causes.”

Agricultural intensification, involving changes in land use and pesticide use, emerged as the most frequently cited factor. However, the study emphasizes that all environmental stressors are interconnected climate-related factors like extreme weather and fire also influence other drivers.

Notably, many threats to insect biodiversity go unexamined in current research. “None of the papers mentioned natural disasters,” noted Assistant Professor Eliza Grames. “No papers looked at human intrusions and disturbance, or the effects of war on insects, or railroads.”

The researchers also identified a bias toward studying pollinators like bees and butterflies. “If we focus too much on bees and butterflies and their conservation, we will miss a lot of other species, most of them in fact,” Halsch said.

Photo Credit: gettyimages-erikkarits