Pests are thriving under El Niño and migrating to southern China causing rice yield losses and a potential food shortage.

Migratory pests from mainland Southeast Asia, thriving under El Niño, are partially driving rice yield losses in southern China, a study led by Peking University has found.

The researchers said the new findings were crucial for ensuring food security in the region through collaborative, international pest control strategies.

The scientists found that during El Niño years, warm, humid weather created favourable breeding conditions in the pest source region, while wind gusts helped them migrate to southern China.

The team from Peking University, Chinese Academy of Sciences, Zhejiang University, Potsdam Institute for Climate Impact Research in Germany and the Laboratory of Dynamic Meteorology in France published their findings in the peer-reviewed journal Nature Food on April 18.

“Continued global warming will not only change the ecological niches of pests but also facilitate the increasing occurrence of crop pests, posing a major obstacle to stabilising food production,” the team said.

The scientists urged international collaboration, which is key for minimising crop loss from pests as the world adapts to climate change.

“Even if pest-receiving countries spare no effort to control pest occurrence, it would not be effective or cost-effective if there is a lack of pest control in pest-donating or pest-breeding countries,” they said.

Rice is a staple food in Asia, the world’s most populated continent.

Asia leads the world in rice production, with China and India both accounting for 26 per cent of total production, followed by Bangladesh which produced 7 per cent in 2023, according to a 2024 report from the Food and Agriculture Organisation of the United Nations.

Corresponding author Wang Xuhui, an associate professor at the College of Urban and Environmental Sciences of Peking University, said given that Asia was a hub of rice production and consumption, understanding how pests proliferated under climate patterns could help develop risk mitigation strategies for the continent.

“The impact of natural hazards tends to cancel out across a country and the world over the course of a year. Imports from unaffected regions can often compensate for areas that experience severe effects and lower production,” he said.

“However, a potential large-scale and synchronised reduction in production in Asia would be difficult to compensate for and would severely impact the entire region. It is important for us to understand how this might happen to prevent a food crisis.”

Strong El Niño events pose a threat to global grain production stability, as they can trigger simultaneous crop yield reductions in multiple grain-producing regions worldwide.

Past research has generally concluded that El Niño remotely correlates with climatic factors such as temperature and rainfall in grain-producing areas, causing a reduction in crop yields.

In the new study, the team analysed the relationship between climate oscillations and crop yield in China from 1980 to 2017.

They found that the connection between El Niño and crop yields in China is influenced not only by local climate variations caused by El Niño, but also by its effects on migratory crop pests, namely rice planthoppers and rice leaf folders that migrate from mainland Southeast Asia to southern China.

“This latter factor, a previously neglected pathway, has exerted even stronger impacts than local climate variability,” they wrote.

First author Wang Chenzhi, who is now a senior researcher at the Leibniz Centre for Agricultural Landscape Research in Germany after receiving his PhD from Peking University in 2022, said the study showed the urgent need for international collaboration in pest control to reduce the risk of food shock in a warming world.

“Our study shows pest management in Southeast Asian countries, such as Thailand, Vietnam, Cambodia and Myanmar, has indirect effects on China’s agricultural output. The issue cannot be solved by China alone – it requires collaboration with neighbouring countries,” he said.

Wang said experts from the region should collaborate to identify and exchange information on common pests, establish a joint monitoring and alert system for pest outbreaks, train local farmers and study the controlled application of insecticides, which are more effective against larvae of rice pests than adults.

He added that under global warming, collaborative cooperation was key to ensuring regional food security and improving the livelihood of farmers in mainland Southeast Asia.

Published Date: May 6, 2025