The molecule behind a Biblical plague?

A simple natural molecule 2-methoxyphenol, also known as guaiacol could be a factor in the voracious swarming of locusts, which have devastated crops since before even Biblical plagues.

A compound to make locusts volatile

The compound is made by the bacterium Pantoea agglomerans which lives in the insects' guts, and according to Rod Dillon at the University of Bath, UK, this volatile chemical component is one component of a pheromone found in desert-locust faecal pellets thought to trigger swarming behaviour. Guaiacol is probably biosynthesised from the lignin-derived vanillic acid (4-hydroxy-3-methoxybenzoic acid) in the locusts' diet.

	Perfume clue to locust swarms

Locusts gather in vast swarms, which leave in their wake devastated human crops and starving villagers in many areas of the developing world. Understanding what makes them swarm might ultimately lead to a pesticide-free method of crop protection.

Perhaps by placing the pheromone over large areas where locusts feed we might be able to disrupt their behavior and stop them swarming. Alternatively, we could use guaiacol or the whole pheromone to trigger them to swarm when no food is available and so bump up their mortality rate.

Nature, 2000, 403, 851.