Beijing is currently contending with a significant infestation of the North American fall webworm (Hyphantria cunea), an invasive species that has blanketed local trees in dense, greyish-white webs. To mitigate the damage caused by the caterpillars as they consume local foliage, municipal authorities have launched a multi-pronged containment strategy. This effort includes the mass release of over one billion parasitic wasps, which act as a natural predator to the larvae, alongside organized community contests that encourage citizens to collect and remove the caterpillars manually.

The fall webworm is the larval stage of a white moth species that has spread rapidly across the region this summer. While the infestation has raised concerns regarding the health of urban and suburban tree populations, authorities have clarified that the insects do not pose a direct physical threat to humans. The use of parasitic wasps represents a biological control method intended to reduce the population of the moths without relying solely on chemical pesticides. The caterpillar-catching competitions serve as both a practical removal effort and a public engagement strategy to address the visible impact of the webs on the local landscape. As the summer progresses, the effectiveness of these combined biological and manual interventions remains a primary focus for local environmental agencies tasked with protecting the city's greenery.