The evolutionary game is accelerating as always, it seems, with the news that cabbage aphids have developed a way of resisting predators by turning themselves into suicide bombers. New research by a joint UK-Norweigan team suggests that the insects disable attackers such as ladybirds by setting off a mustard oil ‘bomb’.

The substance kills, injures or repels the assailant, which saves the colony from attack, although the individual aphid involved usually dies in the process.

When aphids feed on cabbages, they consume chemicals called glucosinolates, which are then stored in their blood. They also produce an enzyme called myrosinase, which is stored in the muscles of their head and thorax. In the event of an attack, the enzyme comes into contact with the glucosinolates, creating a violent chemical reaction that releases mustard oil.

The research team from the UK and Norway reportedly confirmed its findings by controlling the diet of different groups of aphids. They found that insects eating a diet rich in glucosinolates had a high success rate in fending off predators, whereas those without them did not.

The results are due to be published in the upcoming issue of Proceedings of the Royal Society: Biological Sciences. It is believed to be the first of its kind to prove they form the basis of a chemical defence system.