Joke Collection Website - News headlines - You can see them in the park, especially those placed artificially on plane trees, with small nails nailed into the trunks. Ask someone who understands what this is for and what is its use? Thanks!

You can see them in the park, especially those placed artificially on plane trees, with small nails nailed into the trunks. Ask someone who understands what this is for and what is its use? Thanks!

This is a tussah pupa that has been parasitized by the wasp Zhoulai (these tussah pupae are mass-produced in the factory and have been artificially inoculated with the wasp Zhoulai). There are holes in the pupa. It facilitates the smooth release of Zhou's wasps, which are natural enemies of forest leaf pests such as American white moths. Using this method for biological control has become a very common practice in urban greening in recent years.