Many visitors to the Mangrove Nature Reserve in south China's Shenzhen City would notice some tinny white things spread on the path, leaves and ground. They look like fallen flowers but if one stares at them, one can observe that they can actually move. 

These white creatures are not flowers or elves in the forest, but the final instar nymphs of Ricania speculum. Ricania speculum, also called black planthopper, is considered a major agricultural pest. The adult planthoppers have dark wings, they can just fly on your shoulder if you walk in the bush and disturb their "napping time." 

The insects have ravaged mangrove forests in Shenzhen in the past. They gather in clusters on twigs and branches and feed on sap. To protect the unique ecosystem of the mangroves, Shenzhen is working on a better way to control the species.

(Video filmed by CGTN Nature filming crew, cover image via VCG.)

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