Pheromone causes locusts to swarm

Locust swarm East Africa

A research project has discovered that the reason why locusts swarm and cause such devastating damage to crops is because of a pheromone that they produce. This triggers a desire to join together and form swarms. When they form a swarm they produce more pheromones which in turn creates a bigger swarm. There is a natural desire by humans to stop this happening because of the massive agricultural and economic losses that locust swarms cause.

Locust swarm East Africa

Locust swarm East Africa. Photo: AP.

It is estimated that this year alone (2020) locust swarms have caused £6.5 billion worth of damage. A swarm of one square kilometre can destroy enough food in a day to feed 35,000 people for a year according to The Times newspaper reporting on this phenomenon.

Canny scientists have figured out three possible ways of stopping swarming locusts. They have discovered that one particular compound, the pheromone, emitted by locusts attracted other locusts which made them come together in a group. This compound is called 4-vinylanisole. The researchers, whose work is published in Nature have identified three ways of using the information.

They could use the pheromone to attract locusts into a trap where they are killed. They could genetically engineer locusts so that they are without the receptor that senses this smelly molecule. And thirdly they could block the receptor in the locusts preventing them from smelling the pheromone. If the modified locusts could breed with the group they’d propogate the modified variants, ending the swarms.

The last solution of the three is probably the most promising. It looks as if it might work and if successful would prevent these catastrophic plagues. Africa is where the stories come from about devastating locust swarms. 2020 has been particularly bad.