Yunnan witnesses largest butterfly emergence in a decade

Photo taken on May 20 shows a small cluster of butterflies in the Butterfly Valley in southwest China's Yunnan Province. The valley is witnessing the largest "butterfly explosion" in a decade. (Hu Chao/Xinhua)

Around 150 million butterflies emerged on Thursday in a valley in southwest China's Yunnan Province, making it the largest surge of butterflies here in a decade.

With a warm and humid climate all year round, the Butterfly Valley in Honghe Hani and Yi Autonomous Prefecture is home to over 400 butterfly species.

From May to June each year, a spectacular "butterfly explosion" appears in the valley as caterpillars break out of cocoons in a short period. They appear in clusters in forests and along the streams and pathways, said Yang Zhenwen, a butterfly observer in the valley.

Photo taken on May 20 shows two women enjoying the view of a "butterfly explosion" in Honghe Hani and Yi Autonomous Prefecture in southwest China's Yunnan Province. (Hu Chao/Xinhua)

Monitoring data show that the aggregate number of butterflies in three major cluster areas in the valley is estimated to be more than three times that of the same period in 2020.

The phenomenon only occurs in Mexico and China's Yunnan. "The ecological environment of the valley is ideal for butterfly breeding, and there are abundant bamboo leaves here which butterflies feed on," said Yang.

The butterfly explosion will last for about 20 days and will likely peak between May 25 and 28, he added.