Chinese scientists find passion fruit can kill fruit fly eggs

 (Xinhua) -- Chinese scientists have recently discovered that passion fruit can directly kill the eggs of fruit flies, providing a new method to control the pest, according to a Science and Technology Daily report published Thursday.

The fruit fly is a major pest species that reduces the yield of commercial fruits, vegetables and nuts. Passion fruit, native to South America, was introduced to south China in 2012 for large-scale commercial planting.

The scientists observed that passion fruit attracted native fruit flies to lay eggs in the fruits, but most of the eggs did not hatch.

Photo taken on Nov. 18, 2021 shows the Passiflora edulis (passion fruit) in Hainan Tropical Botanical Garden in Danzhou City, south China's Hainan Province. (Xinhua/Pu Xiaoxu)

According to Wu Weijian at South China Agricultural University, the lead researcher of the study, when a fruit fly penetrates into the middle layer of the fruit wall to lay eggs, it causes the plant tissue to break down and release hydrogen cyanide, which kills most of the eggs.

Wu said this is the first instance of finding a living plant which can directly kill the eggs of pests in the study of interaction between plants and herbivorous insects.

Passion fruit can be recommended as a pest trap crop to plant at the border of an orchard or melon field to control fruit flies, said Liao Yonglin at Guangdong Academy of Agricultural Sciences, one of the researchers.

Although ecological traps can usually be offset by the learning ability or evolution of herbivorous insects, the ecological trap provided by passion fruit may be permanent in the case of fruit flies, according to the study which was published in the journal Pest Management Science.