Controlling agricultural pests

RNA, good for vaccines, can also be used as a pesticide

A new approach to debugging

RIBONUCLEIC ACID (RNA), once little-known outside biological circles, has recently become the molecule de nos jours. The reason is its role in covid-19 vaccines. The RNA molecules in these encode spike, a coronavirus protein. So, when the protein-making machinery of a body cell encounters such RNA, spike is what it makes. That lets a vaccine-recipient’s immune system learn to recognise a crucial part of the enemy before the real thing turns up.

Helping to make proteins is not, however, RNA’s only job. Among many other things it is central to a process called RNA interference, which prevents, rather than facilitates, the manufacture of specific proteins. RNAi, as this activity is called for short, has also been investigated medically. It has been approved for use against four genetic diseases and is under investigation for the treatment of more than a dozen others. That is good. Some biologists, though, think RNAi may have an important non-medical use as well, as a precisely targeted, environmentally friendly pesticide.

The theory is simple. Identify a protein crucial to the survival of the pest in question. Tailor a specific interfering RNA molecule to sabotage production of that protein. Deliver…