Scientists Find Chemical That Causes Crop-Destroying Insects to Gather

Category: Science/Environment


Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. locust / ˈloʊ kəst / (n) – a plant-eating insect that travels in large groups and is characterized by its long legs

    Locusts destroyed the farmer’s crops.

  2. swarm / swɔrm / (v) – to fly together in a group

    I saw some bees swarming.

  3. emit / ɪˈmɪt / (v) – to send out something from a source

    The sounds emitted by the whales were captured by our underwater microphone.

  4. migratory / ˈmaɪ grəˌtɔr i / (adj) – describing someone/something that moves or travels from one place to another at different times of the year

    The crane is a type of migratory bird that travels from Siberia to Izumi every winter.

  5. solitary / ˈsɒl ɪˌtɛr i / (adj) – done or existing by oneself

    The solitary building stands out.


Read the text below.

Scientists have identified a chemical that causes locusts to swarm.

The chemical, called 4-vinylanisole (4VA), is emitted by migratory locusts from their back legs. As other locusts detect 4VA, they become attracted to it, causing them to form destructive swarms.

According to the scientists, their discovery of 4VA may help in coming up with new ways to regulate or stop locust swarms.

For their research, the scientists looked for specific chemicals emitted only by sociable locusts. They identified six scents and tested whether any of them could attract solitary locusts. They found that 4VA attracted both solitary and sociable locusts regardless of their sex and age.

Findings also showed that the size of a swarm was dependent on the amount of 4VA in the air. The scientists observed that a swarm grew bigger when there was an increase in 4VA concentration in the air.

Lead researcher Le Kang explained that locust outbreaks cause enormous agricultural and economic losses worldwide.

Currently, using pesticides is the only effective method to suppress locust outbreaks.  However, these chemicals can harm plants, animals, and even humans.

The researchers suggested safer and more targeted approaches to fight swarms. One suggestion was to create a chemical to block the effect of 4VA. Another was to use an artificial 4VA scent to attract locusts and destroy them.

Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

• Do you agree with the scientists’ suggestions (i.e. creating a chemical to block the effect of 4VA or using an artificial 4VA scent) to stop swarms? Why or why not?
• In your opinion, who will greatly benefit from the findings of the study (e.g. farmers)? Discuss.

Discussion B

• Aside from locusts, what other insects or pests do you think scientists should do a similar study on? Explain.
• In your opinion, should scientists create ways to stop a natural phenomenon like insect swarms? Why or why not?