A simplified version of the DARPA programme could therefore find military application as a means of making plants die.

In 1975, the Biological Weapons Convention entered into force. The 182 states that have so far become party to the Convention, including the USA, undertake never to develop or produce microbial or other biological agents or toxins “whatever their origin or method of production, of types and in quantities that have no justification for prophylactic, protective or other peaceful purposes”. They also commit not to develop “weapons, equipment or means of delivery designed to use such agents or toxins for hostile purposes or in armed conflict”. The researchers argue that the insects employed to deliver the viruses in the DARPA programme might be perceived as such “means of delivery”.

“Because of the broad ban of the Biological Weapons Convention, any biological research of concern must be plausibly justified as serving peaceful purposes,” states Professor Silja Vöneky, who holds the Chair of International Law and Ethics of Law at the University of Freiburg.