The insect radar technology developed by the Beijing Institute of Technology (BIT) research team has helped China build the world's largest monitoring network for migratory crop pests, offering round-the-clock protection of the country's grain production.

Eight of the 11 Class-A crop pests on China's list are long-distance migrants that can ride seasonal winds across hundreds of kilometers overnight. From 2021 to 2024, these eight pests reached an average of 1.25 billion mu (83 million hectares) of grain fields each year, accounting for roughly 40 percent of all pest occurrences on China's three staple crops.

In collaboration with partner institutions, BIT researchers have developed a family of insect radars capable of tracking in real time where pests come from, how many there are and where they are heading. The systems can pick up a rice planthopper, an insect roughly one millimeter in size, from several hundred meters away.

"Finding a 1-millimeter rice planthopper in the open sky is like searching for a needle in a haystack," said Professor Hu Cheng of BIT. "Our breakthrough is that the radar simultaneously emits multiple wavelengths of different precision — like using multiple rulers of different scales to measure the insects — so we can detect very large pests and very small ones at the same time."

Hu noted that the radar has gone through several generations since the first prototype rolled off the production line in 2018. "Detection accuracy is already very high. Our next priority is to refine the species-recognition rate through long-term data accumulation," he added.

To date, 65 insect radars across the country have been linked to a national monitoring and early-warning platform, covering the country's three major pest migration corridors and giving China the world's largest such network. It is expected to expand the total to more than 150 radars by 2030, achieving full coverage of principal migration routes with no blind spots in core agricultural regions.