Beijing fights invasive moths with parasitic wasps and caterpillar-catching contests

Authorities in the Chinese capital are releasing more than a billion parasitic wasps and encouraging caterpillar-catching competitions to try to contain the spread of the invasive North American fall webworm.

The caterpillars have blanketed trees in Beijing and surrounding areas this summer, spinning clouds of greyish-white webs as they eat their way through foliage. The insects are the fuzzy larval stage of…